WO2020136327A1 - Colouring by optical interference of a diamond - Google Patents

Colouring by optical interference of a diamond Download PDF

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Publication number
WO2020136327A1
WO2020136327A1 PCT/FR2019/053165 FR2019053165W WO2020136327A1 WO 2020136327 A1 WO2020136327 A1 WO 2020136327A1 FR 2019053165 W FR2019053165 W FR 2019053165W WO 2020136327 A1 WO2020136327 A1 WO 2020136327A1
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Prior art keywords
layer
diamond
coating layer
buried layer
buried
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PCT/FR2019/053165
Other languages
French (fr)
Inventor
Samuel Saada
Hugues Girard
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Commissariat A L'energie Atomique Et Aux Energies Alternatives
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Publication of WO2020136327A1 publication Critical patent/WO2020136327A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • A—HUMAN NECESSITIES
    • A44—HABERDASHERY; JEWELLERY
    • A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
    • A44C17/00—Gems or the like
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/04—Coating on selected surface areas, e.g. using masks
    • C23C14/042—Coating on selected surface areas, e.g. using masks using masks
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/18—Metallic material, boron or silicon on other inorganic substrates
    • C23C14/185—Metallic material, boron or silicon on other inorganic substrates by cathodic sputtering
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/006—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterized by the colour of the layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/04—Coating on selected surface areas, e.g. using masks
    • C23C16/042—Coating on selected surface areas, e.g. using masks using masks
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/26—Deposition of carbon only
    • C23C16/27—Diamond only
    • C23C16/274—Diamond only using microwave discharges
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates

Definitions

  • the invention relates to the field of diamond coloring, in particular of diamonds intended for jewelry.
  • An interference color (or structural color for “structural color” in English) is a color produced by optical interference, a structural element (for example a thin layer) of a dimension close to the incident wavelength of light visible.
  • visible light ranges from 380 nm (purple) to 700 nm (red).
  • solid diamond Concerning the coloring of a diamond (hereinafter “solid diamond”) via an interference layer, it is necessarily necessary that the optical properties of the solid diamond and of the interference layer, deposited on the surface of the solid diamond, be different (variation of refractive index) so that there is a reflection at the diamond / deposited layer interface: this is a necessary condition for obtaining optical interference.
  • Diamond heavily doped with boron has different optical properties than that of undoped diamond. Also, the deposition of a layer of boron-doped diamond on an undoped solid diamond makes it possible to obtain a coloration of the solid diamond and to preserve the properties of the diamond on the surface. Highly doped diamond has "mechanical" properties almost identical to that of undoped diamond. But in this case, the coloring is provided by the doping of the layer, which varies from light blue to blue / dark brown depending on the amount of doping.
  • the optical properties of a layer of moderately doped diamond and of undoped diamond are not very different, which means that the reflection at the diamond / doped diamond interface is very low and the coloring by interference not visible;
  • the optical properties of a highly doped diamond layer are different from the intrinsic diamond; but in this case, the layer has a very marked color (brown / dark blue) due to the fact that the layer is relatively absorbent in the visible; therefore, the color due to doping takes precedence over the interference color.
  • the objective sought is to obtain a colored diamond, according to a wide choice of colors, while retaining the surface properties of the diamond (hardness, chemical resistance, abrasion resistance, etc.).
  • main diamond body having at least one face
  • a structure for coloring said face by optical interference comprising a buried semi-transparent or opaque layer, having a refractive index ni, which is arranged on the face of the main body, and a coating layer diamond, having a refractive index r ⁇ 2, which completely covers the buried layer;
  • the buried layer being able to reflect an incident beam of visible light refracted by the coating layer and the coating layer being capable of providing coloring by interference between an incident beam of visible light reflected by an external surface of the coating layer and a beam refracted by the coating layer after reflection on the buried layer.
  • the interference coloring occurs between the beam 21 and the beam 24.
  • the gem is qualified as “composite” because it comprises several elements, namely the main diamond body, the buried layer and the diamond coating layer.
  • the semi-transparent or opaque buried layer creates a reflection interface and allows the coating layer to form an interference layer and generate an interference color.
  • the coating layer also has the function of protecting the buried layer, providing the composite gem with surface properties of the diamond. Thanks to the coloring structure resulting from the association of the buried layer and the coating layer, the buried layer will appear in the form of a colored pattern, in the visible, when it is viewed in visible light reflected at across the coating layer.
  • the buried layer is semi-transparent or opaque. It cannot be transparent, because it must create a reflection interface. The more the semi-transparent layer tends to be opaque, the more intense the interference color will be; however, the more opaque the buried layer, the more you lose the benefits of multiple internal reflections of the underlying solid diamond (i.e. the main diamond body), provided by the size of said solid diamond.
  • the diamond coating layer is substantially transparent.
  • the coating layer can be in polycrystalline diamond or in homoepitaxial diamond (that is to say almost monocrystalline).
  • interference coloring designates a coloration obtained by the reflection of incident light visible on the surface of the coating layer, associated with the reflection of the incident light on the buried layer (diamond layer / buried layer interface).
  • the colorimetric contribution of the coloring structure depends mainly on the thickness of the coating layer. Thus, by varying the thickness of this coating layer, one has access to a large choice of colors among the colors of the chromatic circle. If the coating layer (for example by doping with boron) and / or the buried layer are colored, their color also contributes to the colorimetric contribution. We will however avoid that the buried layer and the coating layer are too colored, in order to prevent their colors from dominating and masking the interference color.
  • substantially transparent layer denote, respectively, a substantially transparent, semi-transparent or opaque layer, at the wavelengths of visible light.
  • substantially transparent means that the light transmission factor is at least 80% (terminal included); the term “semi-transparent” means that the light transmission factor is at least 10% (terminal included) and at most 80% (terminal excluded); the term “opaque” means that the light transmittance is less than 10%.
  • the main body is a cut diamond, for example a diamond intended for jewelry.
  • a cut diamond 1 is faceted with cuts to create a table 2, a crown 3 (which includes stars 6, halefis 7 and bezels 8 (or table corners)), a rondiste 4 and a cylinder head 5 ( Figure la and lb).
  • the side to be colored will preferably be the side corresponding to the table.
  • the buried layer has a thickness greater than or equal to 5 nm. Since the buried layer can be opaque, it can perfectly well have a thickness of up to 20 ⁇ m. In the particular case where the buried layer is metallic, the layer is already optically opaque for a thickness of 100 nm; the deposition of a buried metallic layer with a thickness greater than 100 nm is therefore of no particular interest.
  • the buried layer has a thickness of between 5 and 100 nm.
  • This range of values was selected because it allows a buried layer having a thickness in this range of values to form a sufficient reflection interface, while allowing transmission of the beam through the buried layer (semi-transparent layer). , to keep the “incoming” light in the main body, or to create an interface with high reflectivity (opaque layer).
  • the buried layer has a thickness between 5 and 50 nm, preferably between 5 and 30 nm.
  • the coating layer has a thickness of between 90 and 2000 nm. This range of values has been selected so as to ensure that the coating layer plays its role of interference layer while remaining substantially transparent. It is further specified that below 90 nm, there is no "visible” interference (that is to say in the field of visible light). Preferably, the coating layer has a thickness of between 100 and 1000 nm.
  • the expression "between ... and " should be understood as including the limits.
  • the thicknesses of the layers can for example be measured by spectroscopic ellipsometry, which makes it possible to obtain measurements with an accuracy to within 2 nm.
  • the buried layer is a metallic layer.
  • the advantage of a metallic layer is that it makes it possible to obtain an opacity with a small thickness (generally around a few tens of nanometers); the buried layer being opaque, the reflectivity will be maximum.
  • the buried layer has a variable thickness.
  • a colored pattern can appear with more transparent areas than others. We thus play on the variation of the transparencies of the pattern created by the buried layer.
  • the buried layer forms a pattern.
  • the buried layer can be a continuous layer or a discontinuous layer.
  • the pattern can be simple (for example a circle, if the layer is deposited in a continuous layer, of constant thickness, using a mask provided with a circular hole) or more complicated, for example in the form of a set of elements of variable shapes, as illustrated in Figure 8.
  • the coating layer has a variable thickness. This allows the observed interference color to be varied.
  • the invention also relates to a method of manufacturing a composite gem as defined above. It includes the following steps:
  • the formation of the buried layer comprises at least two successive deposits of the material of the buried layer, produced by lithography and / or with different masks. This allows a pattern to appear with more transparent areas than others.
  • the formation of the coating layer comprises an operation chosen from:
  • At least two successive deposits of the diamond material of the coating layer for example by chemical vapor deposition, carried out with different masks;
  • a deposition of a diamond layer for example by chemical vapor deposition, followed by etching of said layer. This makes it possible to vary the interference color perceived by an observer.
  • both the first and second variants above are produced, in order to have both a variation of transparencies and a variation of colors.
  • the invention finally relates to a method for recovering the main body of a composite gem obtained according to the manufacturing method as defined above.
  • This recovery process includes the following successive steps:
  • openings for example holes, trenches, etc. of nanometric or micrometric dimensions, in the thickness of the coating layer until reaching the buried layer;
  • a chemical attack agent for example an acid chosen to obtain a selective attack on the buried layer, so as to detach the main body from the coating layer;
  • FIGS la and lb show a cut diamond 1 in a top view ( Figure la) and in a sectional view along line II ( Figure lb);
  • - Figure 2 already described, shows, in a sectional view, the path of an incident beam when it crosses a diamond coating layer, deposited directly on a diamond substrate (prior art);
  • FIG. 3 shows, in a sectional view, the path of an incident beam when it crosses a diamond coating layer covering a buried layer, having optical properties different from that of the coating layer, deposited on a diamond substrate (according to the invention);
  • FIGS. 4a and 4b are schematic views, in a sectional view, of steps according to a first embodiment of the method of manufacturing a composite gem according to the invention
  • FIGS. 5a and 5b are schematic views, in a sectional view, of steps according to a second embodiment of the method of manufacturing a composite gem according to the invention.
  • FIGS. 6a to 6d are schematic views, in a sectional view, of steps according to a third embodiment of the method of manufacturing a composite gem according to the invention.
  • FIG. 7 is a photograph of a composite gem obtained according to an embodiment of the invention.
  • FIGS. 11a to 11c are schematic views, in a sectional view, of steps according to one embodiment of the method for recovering the main diamond body according to the invention.
  • the method according to the invention makes it possible to create an interference type coloring on the surface of a diamond, while retaining the properties of the diamond on the surface of the diamond gemstone (natural or synthetic).
  • an ultra-thin layer 12 of a material having optical properties different from that of diamond is buried between a face of the solid diamond (main body 10) and the diamond coating layer 11 (FIG. 3).
  • the coating layer 11 has an outer face and an inner face, which is in optical contact with the buried layer 12.
  • the ultra-thin layer 12 will thus make it possible to create a reflection interface and the coating layer 11 in diamond, which is thin enough to serve as an interference layer.
  • the association of the buried layer 12 and the coating layer 11 creates a coloring structure 13 which, makes it possible to generate optical interference, which leads to interference coloring of the solid diamond 10.
  • an incident light beam 20 is reflected by the external face of the coating layer (reflected beam 21) and is refracted while passing through the coating layer (beam refracted 22); part of the beam passes through the buried layer (transmitted beam 25); the refracted beam 22 is reflected by the buried layer 12 (refracted then reflected beam 23); the beam 23 is refracted by passing through the external face of the coating layer (beam 24).
  • the coating layer being a thin layer, there is optical interference between the beam 21 and the beam 24.
  • the substrate is a monocrystalline diamond (natural or synthetic).
  • it may be a diamond gemstone intended for jewelry.
  • the buried layer is thin; preferably, its thickness is adapted so that it is semi-transparent and so that “incoming” light is preserved in the underlying solid diamond.
  • the buried layer is metallic, it has a thickness of less than 50 nm in order to be semi-transparent.
  • the buried layer has a different refractive index than the diamond of the coating layer.
  • This buried layer is preferably a metallic layer (pure metal, metallic alloy or metallic oxide) and is, preferably deposited by PVD deposit.
  • the metal layer can for example be chosen from Cr, Pt, Ir, W, Ti, etc.
  • the coating layer which serves as both a protective layer and an interference layer, is a thin layer (preferably, a thickness between 100 nm to 1 ⁇ m) and is made of diamond. It can be a polycrystalline diamond (for example obtained by CVD deposition). As illustrated in FIGS. 4a and 4b, for a coating layer 11 made of polycrystalline diamond, nucleation takes place on the buried ultra-thin layer 12 (FIG. 4a) and the coating layer 11 made of polycrystalline diamond thus obtained comprises joints grains 14 ( Figure 4b).
  • Step 1 cleaning the sample ( Figure 6a)
  • the sample (hereinafter solid diamond, main body 10 or substrate) is here a jewelry diamond having a main face which it is desired to color.
  • the sample is cleaned by immersion in a 50/50 ethanol / acetone solution placed in an ultrasonic bath for 15 minutes. It is then rinsed with ultra-pure water and dried under a stream of nitrogen.
  • Step 2 masking and depositing a layer of chromium ( Figure 6b)
  • the buried layer is a layer of chromium. It can be deposited by physical vapor deposition (PVD). To do this, the sample is placed on a substrate holder and a mask is placed on the side to be colored.
  • the mask can be a metal sheet pierced with a pattern which is chosen according to the colored pattern that one wishes to obtain; in the embodiment, the pattern of the mask is a circle, so as to obtain a colored disc on the face of the sample.
  • the assembly is then placed in a PVD-magnetron type reactor at 13.56 MHz.
  • the target is in chrome.
  • a secondary vacuum ( ⁇ 10 6 mBar) is produced in the reactor via a turbomolecular pump and is maintained for 2 hours. Once the desired secondary vacuum is obtained, the deposition is carried out.
  • the deposition of a 30 nm chromium layer is obtained by applying the following parameters:
  • Target self-bias voltage 650 V
  • Step 3 deposit of diamond nanocrystals on the surface of the substrate (“nanoseeding” in English) ( Figure 6c)
  • the substrate covered with an ultra thin layer of chromium is immersed in a solution of poly (dimethyl diallyl ammonium chloride) diluted to 0.2% by mass in ultra-pure water for a period of 15 minutes.
  • the substrate covered with a layer of chromium and diamond nanoparticles is then introduced into a CVD growth reactor assisted by microwave plasma at 2.45 GHz, an MPCVD reactor generally used for growing diamond films.
  • the substrate is placed on a substrate holder and a mask (for example a molybdenum mask) can be placed on the substrate in order to exclude from growth certain faces of the substrate.
  • a secondary vacuum ( ⁇ 10 6 mBar) is produced via a turbomolecular pump and is maintained for 2 hours.
  • FIG. 7 A photograph of the composite gem 100 thus obtained is presented in FIG. 7. It can be seen that a colored disc appears in the main face of the diamond (main face which corresponds to table 2).
  • the achievable patterns, as well as the possible colors are multiple.
  • the thickness of the buried layer can be varied to reveal a colored pattern having more "transparent" areas than others.
  • a colored pattern for example in green, with different levels of transparency: a large light circle encompassing darker elements (including a smaller central circle, surrounded by triangles). This can be obtained by a first deposit of chromium with a mask having a hole of the diameter of the clear circle; then a second deposit with another mask having a central hole surrounded by triangles.
  • the elements of the buried layer having a greater thickness in the parts obtained following the second deposition are the elements appearing darker.
  • a large circle for example in dark purple
  • a smaller central circle surrounded by triangles, which are dark green.
  • This can be obtained by depositing a layer of uniform thickness in the form of a circle for the buried layer and covering this buried layer with a layer of variable thickness for the diamond layer, the zones formed with a constant thickness of buried layer and a first thickness of diamond layer forming the zones in dark purple and the zones formed of a constant thickness of buried layer and a second thickness of diamond layer forming the zones in dark green.
  • micro-perforations 16 in the thickness of the diamond coating layer 11 until reaching the buried ultra-thin layer 12 (FIG. 11b).
  • the diamond substrate 10 can be recovered (FIG. 11c).
  • the buried layer is metallic, if we soak the composite gem in an acid capable of dissolving this metallic layer, we will recover the precious gemstone intact, because the diamond does not react with the acid. This allows you to simply erase a pattern created on a diamond gemstone, without altering the stone.

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  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
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  • Crystals, And After-Treatments Of Crystals (AREA)
  • Chemical Vapour Deposition (AREA)
  • Surface Treatment Of Optical Elements (AREA)
  • Laminated Bodies (AREA)

Abstract

Disclosed is a composite gem (100) comprising: - a main body (10) made of diamond having a face; - a structure (13) for colouring said face by optical interference, comprising a semi-transparent or opaque embedded layer (12), of refractive index n1, disposed on the face of the main body, and a covering layer (11) made of diamond, of refractive index n2, completely covering the embedded layer; the difference between n1 and n2, in absolute value, being greater than or equal to 0.1; the embedded layer being capable of reflecting a refracted incident beam of visible light (22) that was refracted by the covering layer, and the covering layer being capable of providing a colouring by interference between a reflected incident beam of visible light (21) that was reflected by an outer surface of the covering layer and a refracted beam (24) that was refracted by the covering layer after reflection on the embedded layer.

Description

COLORATION PAR INTERFERENCE OPTIQUE D'UN DIAMANT COLOR BY OPTICAL INTERFERENCE OF A DIAMOND
DESCRIPTIONDESCRIPTION
DOMAINE TECHNIQUE TECHNICAL AREA
L'invention se rapporte au domaine de la coloration du diamant, notamment de diamants destinés à la joaillerie. The invention relates to the field of diamond coloring, in particular of diamonds intended for jewelry.
ÉTAT DE LA TECHNIQUE ANTÉRIEURE STATE OF THE PRIOR ART
Il existe de nombreuses façons de colorer des diamants, notamment par irradiation/recuit du diamant, par dépôt d'une couche d'un matériau coloré sur la surface du diamant ou bien encore par dépôt d'une couche mince en surface pour obtenir une couleur interférentielle. There are many ways to color diamonds, in particular by irradiating / annealing the diamond, by depositing a layer of colored material on the surface of the diamond or even by depositing a thin layer on the surface to obtain a color. interference.
Une couleur interférentielle (ou couleur structurelle pour « structural color » en anglais) est une couleur que produit, par interférences optiques, un élément structurel (par exemple une couche mince) d'une dimension proche de la longueur d'onde incidente de la lumière visible. On rappelle que la lumière visible s'étend de 380 nm (violet) à 700 nm (rouge). An interference color (or structural color for “structural color” in English) is a color produced by optical interference, a structural element (for example a thin layer) of a dimension close to the incident wavelength of light visible. Remember that visible light ranges from 380 nm (purple) to 700 nm (red).
Concernant la coloration d'un diamant (ci-après « diamant massif ») via une couche interférentielle, il faut nécessairement que les propriétés optiques du diamant massif et de la couche interférentielle, déposée en surface du diamant massif, soient différentes (variation d'indice de réfraction) pour qu'il y ait une réflexion à l'interface diamant/couche déposée : c'est une condition nécessaire pour obtenir une interférence optique. Concerning the coloring of a diamond (hereinafter "solid diamond") via an interference layer, it is necessarily necessary that the optical properties of the solid diamond and of the interference layer, deposited on the surface of the solid diamond, be different (variation of refractive index) so that there is a reflection at the diamond / deposited layer interface: this is a necessary condition for obtaining optical interference.
Par conséquent, si on dépose une couche mince 11 de diamant (de synthèse) sur un diamant massif 10 (naturel ou de synthèse), les propriétés optiques étant similaires (ou extrêmement proches), il n'y a pas génération d'interférence, donc pas de coloration par interférence (figure 2). Consequently, if a thin layer 11 of diamond (synthetic) is deposited on a solid diamond 10 (natural or synthetic), the optical properties being similar (or extremely close), there is no generation of interference, therefore no staining by interference (Figure 2).
Pourtant, le fait de colorer un diamant massif via une couche de diamant serait très intéressant, car cela permettrait de conserver les propriétés du diamant sur toutes les surfaces de la pierre (dureté, résistance à la rayure, résistance chimique, etc.). However, the fact of coloring a solid diamond via a layer of diamond would be very interesting, because it would preserve the properties of the diamond on all surfaces of the stone (hardness, scratch resistance, chemical resistance, etc.).
Le diamant fortement dopé au bore présente des propriétés optiques différentes de celle du diamant non dopé. Aussi, le dépôt d'une couche en diamant dopé au bore sur un diamant massif non dopé permet d'obtenir une coloration du diamant massif et de conserver les propriétés du diamant en surface. Le diamant fortement dopé présente des propriétés « mécaniques » quasi identiques à celle du diamant non dopé. Mais dans ce cas, la coloration est apportée par le dopage de la couche, qui varie du bleu clair au bleu/brun foncé en fonction de la quantité de dopage. Diamond heavily doped with boron has different optical properties than that of undoped diamond. Also, the deposition of a layer of boron-doped diamond on an undoped solid diamond makes it possible to obtain a coloration of the solid diamond and to preserve the properties of the diamond on the surface. Highly doped diamond has "mechanical" properties almost identical to that of undoped diamond. But in this case, the coloring is provided by the doping of the layer, which varies from light blue to blue / dark brown depending on the amount of doping.
Cette solution n'est pas satisfaisante pour trois raisons : This solution is not satisfactory for three reasons:
- la gamme de couleurs disponibles par le dopage est très réduite ; - the range of colors available through doping is very small;
- les propriétés optiques d'une couche en diamant moyennement dopé et du diamant non dopé ne sont pas très différentes, ce qui fait que la réflexion à l'interface diamant/diamant dopé est très faible et la coloration par interférence non visible ; the optical properties of a layer of moderately doped diamond and of undoped diamond are not very different, which means that the reflection at the diamond / doped diamond interface is very low and the coloring by interference not visible;
- les propriétés optiques d'une couche en diamant fortement dopé (concentration en bore supérieure à 3.1020 cm 3) sont différentes du diamant intrinsèque ; mais dans ce cas, la couche possède une couleur très marquée (brun/bleu foncé) due au fait que la couche est relativement absorbante dans le visible ; de ce fait, la couleur due au dopage prend le pas sur la couleur interférentielle. - the optical properties of a highly doped diamond layer (boron concentration greater than 3.10 20 cm 3 ) are different from the intrinsic diamond; but in this case, the layer has a very marked color (brown / dark blue) due to the fact that the layer is relatively absorbent in the visible; therefore, the color due to doping takes precedence over the interference color.
EXPOSÉ DE L'INVENTION STATEMENT OF THE INVENTION
L'objectif recherché est d'obtenir un diamant coloré, selon un choix de couleurs étendu, tout en conservant les propriétés de surface du diamant (dureté, résistance chimique, résistance à l'abrasion, etc.). The objective sought is to obtain a colored diamond, according to a wide choice of colors, while retaining the surface properties of the diamond (hardness, chemical resistance, abrasion resistance, etc.).
Cet objectif est atteint grâce à une gemme composite comprenant : This objective is achieved thanks to a composite gem comprising:
- un corps principal en diamant, ayant au moins une face ; et - a main diamond body, having at least one face; and
- une structure de coloration de ladite face par interférence optique, comprenant une couche enterrée semi-transparente ou opaque, ayant un indice de réfraction ni, qui est disposée sur la face du corps principal, et une couche de revêtement en diamant, ayant un indice de réfraction r\2, qui recouvre complètement la couche enterrée ; a structure for coloring said face by optical interference, comprising a buried semi-transparent or opaque layer, having a refractive index ni, which is arranged on the face of the main body, and a coating layer diamond, having a refractive index r \ 2, which completely covers the buried layer;
la différence entre ni et r\2, en valeur absolue, étant supérieure ou égale à 0,1 ; et the difference between ni and r \ 2, in absolute value, being greater than or equal to 0.1; and
la couche enterrée étant apte à réfléchir un faisceau incident de lumière visible réfracté par la couche de revêtement et la couche de revêtement étant apte à fournir une coloration par interférence entre un faisceau incident de lumière visible réfléchi par une surface externe de la couche de revêtement et un faisceau réfracté par la couche de revêtement après réflexion sur la couche enterrée. the buried layer being able to reflect an incident beam of visible light refracted by the coating layer and the coating layer being capable of providing coloring by interference between an incident beam of visible light reflected by an external surface of the coating layer and a beam refracted by the coating layer after reflection on the buried layer.
Comme on le verra dans la figure 3, la coloration par interférence se produit entre le faisceau 21 et le faisceau 24. As will be seen in FIG. 3, the interference coloring occurs between the beam 21 and the beam 24.
Dans le cadre de la présente demande, la gemme est qualifiée de « composite » car elle comporte plusieurs éléments, à savoir le corps principal en diamant, la couche enterrée et la couche de revêtement en diamant. In the context of the present application, the gem is qualified as “composite” because it comprises several elements, namely the main diamond body, the buried layer and the diamond coating layer.
La couche enterrée semi-transparente ou opaque crée une interface de réflexion et permet à la couche de revêtement de former une couche interférentielle et de générer une couleur interférentielle. La couche de revêtement a également pour fonction de protéger la couche enterrée, assurant à la gemme composite des propriétés de surface du diamant. Grâce à la structure de coloration résultant de l'association de la couche enterrée et de la couche de revêtement, la couche enterrée va apparaître sous la forme d'un motif coloré, dans le visible, lorsqu'elle est visualisée en lumière visible réfléchie au travers de la couche de revêtement. The semi-transparent or opaque buried layer creates a reflection interface and allows the coating layer to form an interference layer and generate an interference color. The coating layer also has the function of protecting the buried layer, providing the composite gem with surface properties of the diamond. Thanks to the coloring structure resulting from the association of the buried layer and the coating layer, the buried layer will appear in the form of a colored pattern, in the visible, when it is viewed in visible light reflected at across the coating layer.
La couche enterrée est semi-transparente ou opaque. Elle ne peut pas être transparente, car elle doit créer une interface de réflexion. Plus la couche semi- transparente tendra à être opaque et plus la couleur interférentielle sera intense ; cependant, plus la couche enterrée est opaque et plus on perd les avantages des réflexions internes multiples du diamant massif sous-jacent (i.e. le corps principal en diamant), assurées par la taille dudit diamant massif. The buried layer is semi-transparent or opaque. It cannot be transparent, because it must create a reflection interface. The more the semi-transparent layer tends to be opaque, the more intense the interference color will be; however, the more opaque the buried layer, the more you lose the benefits of multiple internal reflections of the underlying solid diamond (i.e. the main diamond body), provided by the size of said solid diamond.
On précise que la couche de revêtement en diamant est sensiblement transparente. La couche de revêtement peut être en diamant polycristallin ou en diamant homoépitaxié (c'est-à-dire quasiment monocristallin). It is specified that the diamond coating layer is substantially transparent. The coating layer can be in polycrystalline diamond or in homoepitaxial diamond (that is to say almost monocrystalline).
Dans le cadre de la présente invention, l'expression « coloration par interférence » ou « coloration par interférence optique » désigne une coloration obtenue par la réflexion de la lumière incidente visible sur la surface de la couche de revêtement, associée à la réflexion de la lumière incidente sur la couche enterrée (interface couche diamant/couche enterrée). In the context of the present invention, the expression “interference coloring” or “optical interference coloring” designates a coloration obtained by the reflection of incident light visible on the surface of the coating layer, associated with the reflection of the incident light on the buried layer (diamond layer / buried layer interface).
L'apport colorimétrique de la structure de coloration est fonction principalement de l'épaisseur de la couche de revêtement. Ainsi, en jouant sur l'épaisseur de cette couche de revêtement, on a accès à un nombreux choix de couleurs parmi les couleurs du cercle chromatique. Si la couche de revêtement (par exemple par dopage au bore) et/ou la couche enterrée sont colorées, leur couleur contribue également à l'apport colorimétrique. On évitera cependant que la couche enterrée et la couche de revêtement soient trop colorées, afin d'éviter que leurs couleurs ne dominent et masquent la couleur interférentielle. The colorimetric contribution of the coloring structure depends mainly on the thickness of the coating layer. Thus, by varying the thickness of this coating layer, one has access to a large choice of colors among the colors of the chromatic circle. If the coating layer (for example by doping with boron) and / or the buried layer are colored, their color also contributes to the colorimetric contribution. We will however avoid that the buried layer and the coating layer are too colored, in order to prevent their colors from dominating and masking the interference color.
Les expressions « couche sensiblement transparente », « couche semi- transparente » et « couche opaque » désignent, respectivement, une couche sensiblement transparente, semi-transparente ou opaque, aux longueurs d'onde de la lumière visible. Le terme « sensiblement transparent » signifie que le facteur de transmission de la lumière est d'au moins 80% (borne incluse) ; le terme « semi- transparent » signifie que le facteur de transmission de la lumière est d'au moins 10% (borne incluse) et d'au plus 80% (borne exclue) ; le terme « opaque » signifie que le facteur de transmission de la lumière est inférieur à 10 %. The expressions “substantially transparent layer”, “semi-transparent layer” and “opaque layer” denote, respectively, a substantially transparent, semi-transparent or opaque layer, at the wavelengths of visible light. The term "substantially transparent" means that the light transmission factor is at least 80% (terminal included); the term “semi-transparent” means that the light transmission factor is at least 10% (terminal included) and at most 80% (terminal excluded); the term "opaque" means that the light transmittance is less than 10%.
De préférence, le corps principal est un diamant taillé, par exemple un diamant destiné à la joaillerie. On rappelle qu'un diamant taillé 1 est facetté avec des coupes pour créer une table 2, une couronne 3 (qui comporte des étoiles 6, des haléfis 7 et des bezels 8 (ou coins de table)), un rondiste 4 et une culasse 5 (figure la et lb). Sur un diamant taillé, la face à colorer sera de préférence la face correspondant à la table. Mais on peut colorer indifféremment une, plusieurs ou toutes les faces supérieures du diamant, c'est-à-dire les facettes incluant la table et la couronne. De préférence, la couche enterrée présente une épaisseur supérieure ou égale à 5 nm. Étant donné que la couche enterrée peut être opaque, elle peut parfaitement avoir une épaisseur allant jusqu'à 20 pm. Dans le cas particulier où la couche enterrée est métallique, la couche est déjà optiquement opaque pour une épaisseur de 100 nm ; le dépôt d'une couche enterrée métallique d'une épaisseur supérieure à 100 nm ne présente donc pas d'intérêt particulier. Preferably, the main body is a cut diamond, for example a diamond intended for jewelry. Recall that a cut diamond 1 is faceted with cuts to create a table 2, a crown 3 (which includes stars 6, halefis 7 and bezels 8 (or table corners)), a rondiste 4 and a cylinder head 5 (Figure la and lb). On a cut diamond, the side to be colored will preferably be the side corresponding to the table. However, one can color one, several or all of the upper faces of the diamond, that is to say the facets including the table and the crown. Preferably, the buried layer has a thickness greater than or equal to 5 nm. Since the buried layer can be opaque, it can perfectly well have a thickness of up to 20 µm. In the particular case where the buried layer is metallic, the layer is already optically opaque for a thickness of 100 nm; the deposition of a buried metallic layer with a thickness greater than 100 nm is therefore of no particular interest.
Selon une caractéristique préférée de l'invention, la couche enterrée présente une épaisseur comprise entre 5 et 100 nm. Cette gamme de valeurs a été sélectionnée, car elle permet à une couche enterrée ayant une épaisseur dans cette plage de valeurs de former une interface de réflexion suffisante, tout en permettant une transmission du faisceau au travers de la couche enterrée (couche semi-transparente), pour conserver la lumière « entrante » dans le corps principal, ou de créer une interface avec une forte réflectivité (couche opaque). Plus l'épaisseur de la couche enterrée sera proche de la limite haute de la plage de valeurs et plus la couche enterrée sera « opaque » et la couleur interférentielle générée par la couche de revêtement en diamant sera plus intense. À l'inverse, plus l'épaisseur sera proche de la limite basse, plus la couche enterrée sera transparente et l'intensité de la coloration interférentielle sera moins intense. De préférence, la couche enterrée présente une épaisseur comprise entre 5 et 50nm, de préférence entre 5 et 30 nm. According to a preferred characteristic of the invention, the buried layer has a thickness of between 5 and 100 nm. This range of values was selected because it allows a buried layer having a thickness in this range of values to form a sufficient reflection interface, while allowing transmission of the beam through the buried layer (semi-transparent layer). , to keep the “incoming” light in the main body, or to create an interface with high reflectivity (opaque layer). The closer the thickness of the buried layer is to the upper limit of the range of values, the more the buried layer will be “opaque” and the more intense the interference color generated by the diamond coating layer. Conversely, the closer the thickness is to the lower limit, the more transparent the buried layer and the intensity of the interference staining will be less intense. Preferably, the buried layer has a thickness between 5 and 50 nm, preferably between 5 and 30 nm.
Selon une autre caractéristique préférée de l'invention, la couche de revêtement présente une épaisseur comprise entre 90 et 2000 nm. Cette gamme de valeurs a été sélectionnée de manière à s'assurer que la couche de revêtement joue son rôle de couche interférentielle tout en restant sensiblement transparente. On précise en outre qu'en dessous de 90 nm, il n'y a pas d'interférence « visible » (c'est-à-dire dans le domaine de la lumière visible). De préférence, la couche de revêtement présente une épaisseur comprise entre 100 et 1000 nm. According to another preferred characteristic of the invention, the coating layer has a thickness of between 90 and 2000 nm. This range of values has been selected so as to ensure that the coating layer plays its role of interference layer while remaining substantially transparent. It is further specified that below 90 nm, there is no "visible" interference (that is to say in the field of visible light). Preferably, the coating layer has a thickness of between 100 and 1000 nm.
Dans le présent exposé, l'expression « compris entre ... et ... » doit être comprise comme incluant les bornes. Les épaisseurs des couches peuvent par exemple être mesurées par ellipsométrie spectroscopique, qui permet d'obtenir des mesures avec une précision à 2 nm près. In the present description, the expression "between ... and ..." should be understood as including the limits. The thicknesses of the layers can for example be measured by spectroscopic ellipsometry, which makes it possible to obtain measurements with an accuracy to within 2 nm.
De préférence, la couche enterrée est une couche métallique. L'avantage d'une couche métallique est qu'elle permet d'obtenir une opacité avec une faible épaisseur (généralement autour de quelques dizaines de nanomètres) ; la couche enterrée étant opaque, la réflectivité sera maximale. Preferably, the buried layer is a metallic layer. The advantage of a metallic layer is that it makes it possible to obtain an opacity with a small thickness (generally around a few tens of nanometers); the buried layer being opaque, the reflectivity will be maximum.
Selon une variante, la couche enterrée présente une épaisseur variable. En faisant varier l'épaisseur de la couche enterrée, on peut faire apparaître un motif coloré avec des zones plus transparentes que d'autres. On joue ainsi sur la variation des transparences du motif créé par la couche enterrée. According to a variant, the buried layer has a variable thickness. By varying the thickness of the buried layer, a colored pattern can appear with more transparent areas than others. We thus play on the variation of the transparencies of the pattern created by the buried layer.
Comme nous venons de le dire, la couche enterrée forme un motif. La couche enterrée peut être une couche continue ou une couche discontinue. Le motif peut être simple (par exemple un cercle, si la couche est déposée selon une couche continue, d'épaisseur constante, à l'aide d'un masque muni d'un trou circulaire) ou plus compliqué, par exemple sous la forme d'un ensemble d'éléments de formes variables, comme illustré dans la figure 8. As we have just said, the buried layer forms a pattern. The buried layer can be a continuous layer or a discontinuous layer. The pattern can be simple (for example a circle, if the layer is deposited in a continuous layer, of constant thickness, using a mask provided with a circular hole) or more complicated, for example in the form of a set of elements of variable shapes, as illustrated in Figure 8.
Selon une autre variante, la couche de revêtement présente une épaisseur variable. Cela permet de varier la couleur interférentielle observée. According to another variant, the coating layer has a variable thickness. This allows the observed interference color to be varied.
L'invention concerne également un procédé de fabrication d'une gemme composite telle que définie ci-dessus. Il comprend les étapes suivantes : The invention also relates to a method of manufacturing a composite gem as defined above. It includes the following steps:
- la fourniture du corps principal en diamant ayant au moins une face ; - supply of the main diamond body having at least one face;
- la formation de la couche enterrée sur ladite au moins une face, par exemple par dépôt physique en phase vapeur ; - The formation of the buried layer on said at least one face, for example by physical vapor deposition;
- la formation de la couche de revêtement en diamant, de manière à recouvrir la couche enterrée. - the formation of the diamond coating layer, so as to cover the buried layer.
Selon une première variante, la formation de la couche enterrée comprend au moins deux dépôts successifs du matériau de la couche enterrée, réalisés par lithographie et/ou avec des masques différents. Cela permet de faire apparaître un motif avec des zones plus transparentes que d'autres. Selon une deuxième variante, la formation de la couche de revêtement comprend une opération choisie parmi : According to a first variant, the formation of the buried layer comprises at least two successive deposits of the material of the buried layer, produced by lithography and / or with different masks. This allows a pattern to appear with more transparent areas than others. According to a second variant, the formation of the coating layer comprises an operation chosen from:
- au moins deux dépôts successifs du matériau diamant de la couche de revêtement, par exemple par dépôt chimique en phase vapeur, réalisés avec des masques différents ; et - At least two successive deposits of the diamond material of the coating layer, for example by chemical vapor deposition, carried out with different masks; and
- un dépôt d'une couche diamant, par exemple par dépôt chimique en phase vapeur, suivi d'une gravure de ladite couche. Cela permet de faire varier la couleur interférentielle perçue par un observateur. a deposition of a diamond layer, for example by chemical vapor deposition, followed by etching of said layer. This makes it possible to vary the interference color perceived by an observer.
Selon une troisième variante, on réalise à la fois les première et deuxième variantes ci-dessus, afin d'avoir à la fois une variation de transparences et une variation de couleurs. According to a third variant, both the first and second variants above are produced, in order to have both a variation of transparencies and a variation of colors.
L'invention concerne enfin un procédé pour récupérer le corps principal d'une gemme composite obtenue selon le procédé de fabrication tel que défini ci-dessus. Ce procédé de récupération comprend les étapes successives suivantes : The invention finally relates to a method for recovering the main body of a composite gem obtained according to the manufacturing method as defined above. This recovery process includes the following successive steps:
- la réalisation d'ouvertures, par exemple des trous, des tranchées, etc. de dimensions nanométriques ou micrométriques, dans l'épaisseur de la couche de revêtement jusqu'à atteindre la couche enterrée ; - making openings, for example holes, trenches, etc. of nanometric or micrometric dimensions, in the thickness of the coating layer until reaching the buried layer;
- la dissolution de la couche enterrée à l'aide d'un agent d'attaque chimique (par exemple un acide) choisi pour obtenir une attaque sélective de la couche enterrée, de manière à détacher le corps principal de la couche de revêtement ; - dissolving the buried layer using a chemical attack agent (for example an acid) chosen to obtain a selective attack on the buried layer, so as to detach the main body from the coating layer;
- un éventuel polissage de la face du corps principal pour supprimer des traces de la couche de revêtement. Cela permet de retrouver le corps principal en diamant monocristallin sans qu'il ait été abîmé par la coloration. - possible polishing of the face of the main body to remove traces of the coating layer. This allows to find the main body in monocrystalline diamond without it being damaged by the coloring.
BRÈVE DESCRIPTION DES DESSINS BRIEF DESCRIPTION OF THE DRAWINGS
La présente invention sera mieux comprise à la lecture de la description d'exemples de réalisation, donnés à titre purement indicatif et nullement limitatif, en faisant référence aux dessins annexés sur lesquels : The present invention will be better understood on reading the description of exemplary embodiments, given for purely indicative and in no way limiting, with reference to the appended drawings in which:
- les figures la et lb représentent un diamant taillé 1 selon une vue de dessus (figure la) et selon une vue en coupe selon la ligne l-l (figure lb) ; - la figure 2, déjà décrite, représente, selon une vue en coupe, le parcours d'un faisceau incident lorsqu'il traverse une couche de revêtement en diamant, déposée directement sur un substrat en diamant (art antérieur) ; - Figures la and lb show a cut diamond 1 in a top view (Figure la) and in a sectional view along line II (Figure lb); - Figure 2, already described, shows, in a sectional view, the path of an incident beam when it crosses a diamond coating layer, deposited directly on a diamond substrate (prior art);
- la figure 3 représente, selon une vue en coupe, le parcours d'un faisceau incident lorsqu'il traverse une couche de revêtement en diamant recouvrant une couche enterrée, ayant des propriétés optiques différentes de celle de la couche de revêtement, déposée sur un substrat en diamant (selon l'invention) ; - Figure 3 shows, in a sectional view, the path of an incident beam when it crosses a diamond coating layer covering a buried layer, having optical properties different from that of the coating layer, deposited on a diamond substrate (according to the invention);
- les figures 4a et 4b sont des vues schématiques, selon une vue en coupe, d'étapes selon un premier mode de réalisation du procédé de fabrication d'une gemme composite selon l'invention ; - Figures 4a and 4b are schematic views, in a sectional view, of steps according to a first embodiment of the method of manufacturing a composite gem according to the invention;
- les figures 5a et 5b sont des vues schématiques, selon une vue en coupe, d'étapes selon un deuxième mode de réalisation du procédé de fabrication d'une gemme composite selon l'invention ; - Figures 5a and 5b are schematic views, in a sectional view, of steps according to a second embodiment of the method of manufacturing a composite gem according to the invention;
- les figures 6a à 6d sont des vues schématiques, selon une vue en coupe, d'étapes selon un troisième mode de réalisation du procédé de fabrication d'une gemme composite selon l'invention ; - Figures 6a to 6d are schematic views, in a sectional view, of steps according to a third embodiment of the method of manufacturing a composite gem according to the invention;
- la figure 7 est une photographie d'une gemme composite obtenue selon un mode de réalisation de l'invention ; - Figure 7 is a photograph of a composite gem obtained according to an embodiment of the invention;
- les figures 8, 9 et 10 sont des vues schématiques, en vue de dessus, de colorations possibles selon l'invention ; - Figures 8, 9 and 10 are schematic views, in top view, of possible colors according to the invention;
- les figures lia à 11c sont des vues schématiques, selon une vue en coupe, d'étapes selon un mode de réalisation du procédé de récupération du corps principal en diamant selon l'invention. - Figures 11a to 11c are schematic views, in a sectional view, of steps according to one embodiment of the method for recovering the main diamond body according to the invention.
Il est à noter que les proportions ne sont pas respectées dans les figures. It should be noted that the proportions are not respected in the figures.
EXPOSÉ DÉTAILLÉ DE MODES DE RÉALISATION PARTICULIERS DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS
Le procédé selon l'invention permet de créer une coloration de type interférentielle en surface d'un diamant, tout en conservant les propriétés du diamant à la surface de la pierre précieuse en diamant (naturel ou synthétique). Pour y parvenir, on veut créer un contraste d'indices de réfraction à l'interface entre deux diamants. Pour ce faire, on enterre une couche ultra-mince 12 d'un matériau ayant des propriétés optiques différentes de celles du diamant entre une face du diamant massif (corps principal 10) et la couche de revêtement en diamant 11 (figure 3). La couche de revêtement 11 a une face externe et une face interne, qui est en contact optique avec la couche enterrée 12. The method according to the invention makes it possible to create an interference type coloring on the surface of a diamond, while retaining the properties of the diamond on the surface of the diamond gemstone (natural or synthetic). To achieve this, we want to create a contrast of refractive indices at the interface between two diamonds. To do this, an ultra-thin layer 12 of a material having optical properties different from that of diamond is buried between a face of the solid diamond (main body 10) and the diamond coating layer 11 (FIG. 3). The coating layer 11 has an outer face and an inner face, which is in optical contact with the buried layer 12.
La couche ultra-mince 12 va ainsi permettre de créer une interface de réflexion et la couche de revêtement 11 en diamant, qui est suffisamment mince pour qu'elle serve de couche interférentielle. L'association de la couche enterrée 12 et de la couche de revêtement 11 crée une structure de coloration 13 qui, permet de générer des interférences optiques, ce qui conduit à une coloration interférentielle du diamant massif 10. The ultra-thin layer 12 will thus make it possible to create a reflection interface and the coating layer 11 in diamond, which is thin enough to serve as an interference layer. The association of the buried layer 12 and the coating layer 11 creates a coloring structure 13 which, makes it possible to generate optical interference, which leads to interference coloring of the solid diamond 10.
Comme illustré dans la figure 3, avec la gemme composite 100 selon l'invention, un faisceau de lumière incidente 20 est réfléchi par la face externe de la couche de revêtement (faisceau réfléchi 21) et est réfracté en traversant la couche de revêtement (faisceau réfracté 22) ; une partie du faisceau traverse la couche enterrée (faisceau transmis 25) ; le faisceau réfracté 22 est réfléchi par la couche enterrée 12 (faisceau réfracté puis réfléchi 23) ; le faisceau 23 est réfracté en traversant la face externe de la couche de revêtement (faisceau 24). La couche de revêtement étant une couche mince, il y a interférence optique entre le faisceau 21 et le faisceau 24. As illustrated in FIG. 3, with the composite gem 100 according to the invention, an incident light beam 20 is reflected by the external face of the coating layer (reflected beam 21) and is refracted while passing through the coating layer (beam refracted 22); part of the beam passes through the buried layer (transmitted beam 25); the refracted beam 22 is reflected by the buried layer 12 (refracted then reflected beam 23); the beam 23 is refracted by passing through the external face of the coating layer (beam 24). The coating layer being a thin layer, there is optical interference between the beam 21 and the beam 24.
Le substrat est un diamant monocristallin (naturel ou synthétique). Il peut par exemple s'agir d'une pierre précieuse en diamant, destinée à la joaillerie. The substrate is a monocrystalline diamond (natural or synthetic). For example, it may be a diamond gemstone intended for jewelry.
La couche enterrée est mince ; de préférence, son épaisseur est adaptée afin qu'elle soit semi-transparente et que de la lumière « entrante » soit conservée dans le diamant massif sous-jacent. Par exemple, lorsque la couche enterrée est métallique, elle a une épaisseur inférieure à 50 nm afin d'être semi-transparente. The buried layer is thin; preferably, its thickness is adapted so that it is semi-transparent and so that “incoming” light is preserved in the underlying solid diamond. For example, when the buried layer is metallic, it has a thickness of less than 50 nm in order to be semi-transparent.
La couche enterrée a un indice de réfraction différent de celui du diamant de la couche de revêtement. Cette couche enterrée est, de préférence, une couche métallique (métal pur, alliage métallique ou oxyde métallique) et est, de préférence, déposée par dépôt PVD. La couche métallique peut par exemple être choisi parmi Cr, Pt, Ir, W, Ti, etc. The buried layer has a different refractive index than the diamond of the coating layer. This buried layer is preferably a metallic layer (pure metal, metallic alloy or metallic oxide) and is, preferably deposited by PVD deposit. The metal layer can for example be chosen from Cr, Pt, Ir, W, Ti, etc.
La couche de revêtement, qui sert à la fois de couche de protection et de couche interférentielle, est une couche mince (de préférence, une épaisseur comprise entre 100 nm à 1 pm) et est en diamant. Il peut s'agir d'un diamant polycristallin (par exemple obtenu par dépôt CVD). Comme illustré dans les figures 4a et 4b, pour une couche de revêtement 11 en diamant polycristallin, la nucléation a lieu sur la couche enterrée 12 ultra-mince (figure 4a) et la couche de revêtement 11 en diamant polycristallin ainsi obtenue comporte des joints de grains 14 (figure 4b). The coating layer, which serves as both a protective layer and an interference layer, is a thin layer (preferably, a thickness between 100 nm to 1 μm) and is made of diamond. It can be a polycrystalline diamond (for example obtained by CVD deposition). As illustrated in FIGS. 4a and 4b, for a coating layer 11 made of polycrystalline diamond, nucleation takes place on the buried ultra-thin layer 12 (FIG. 4a) and the coating layer 11 made of polycrystalline diamond thus obtained comprises joints grains 14 (Figure 4b).
Pour obtenir une couche monocristalline couvrante, on peut créer des ouvertures contrôlées (par gravure chimique ou sèche) dans la couche enterrée 12 (figure 5a), puis reprendre la croissance homoépitaxique par CVD sur le substrat 10 (figure 5b). Il faut dans ce cas que la distance qui sépare deux ouvertures soit largement inférieure à deux fois l'épaisseur du revêtement diamant. Par souci de simplification, ces distances ne sont pas respectées dans les figures 5a et 5b. La possibilité de faire croire une couche de revêtement monocristalline augmente fortement l'adhérence de cette couche, puisqu'elle se trouve liée en différents points au diamant massif (substrat). To obtain a covering monocrystalline layer, it is possible to create controlled openings (by chemical or dry etching) in the buried layer 12 (FIG. 5a), then resume homoepitaxial growth by CVD on the substrate 10 (FIG. 5b). In this case, the distance between two openings must be much less than twice the thickness of the diamond coating. For the sake of simplification, these distances are not respected in FIGS. 5a and 5b. The possibility of making a monocrystalline coating layer appear to greatly increase the adhesion of this layer, since it is linked at various points to the solid diamond (substrate).
Nous allons à présent décrire un exemple de réalisation du procédé selon l'invention. We will now describe an exemplary embodiment of the method according to the invention.
Etape 1 : nettoyage de l'échantillon (figure 6a) Step 1: cleaning the sample (Figure 6a)
L'échantillon (ci-après diamant massif, corps principal 10 ou substrat) est ici un diamant de joaillerie ayant une face principale que l'on souhaite colorer. L'échantillon est nettoyé via une immersion dans une solution 50/50 éthanol/acétone placée dans un bain à ultra-sons pendant 15 minutes. Il est ensuite rincé à l'eau ultra-pure et séché sous flux d'azote. The sample (hereinafter solid diamond, main body 10 or substrate) is here a jewelry diamond having a main face which it is desired to color. The sample is cleaned by immersion in a 50/50 ethanol / acetone solution placed in an ultrasonic bath for 15 minutes. It is then rinsed with ultra-pure water and dried under a stream of nitrogen.
Etape 2 : masquage et dépôt d'une couche de chrome (figure 6b) Step 2: masking and depositing a layer of chromium (Figure 6b)
Dans cet exemple de réalisation, la couche enterrée est une couche de chrome. Elle peut être déposée par dépôt physique en phase vapeur (PVD). Pour ce faire, l'échantillon est placé sur un porte-substrat et un masque est placé sur la face à colorer. Le masque peut être une feuille métallique percée d'un motif qui est choisi en fonction du motif coloré que l'on souhaite obtenir ; dans le mode de réalisation, le motif du masque est un rond, de manière à obtenir un disque coloré sur la face de l'échantillon. In this exemplary embodiment, the buried layer is a layer of chromium. It can be deposited by physical vapor deposition (PVD). To do this, the sample is placed on a substrate holder and a mask is placed on the side to be colored. The mask can be a metal sheet pierced with a pattern which is chosen according to the colored pattern that one wishes to obtain; in the embodiment, the pattern of the mask is a circle, so as to obtain a colored disc on the face of the sample.
L'ensemble est ensuite placé dans un réacteur de type PVD-magnétron à 13,56 MHz. La cible est en chrome. Un vide secondaire (<10 6 mBar) est réalisé dans le réacteur via une pompe turbomoléculaire et est maintenu pendant 2 heures. Une fois que le vide secondaire souhaité est obtenu, on réalise le dépôt. The assembly is then placed in a PVD-magnetron type reactor at 13.56 MHz. The target is in chrome. A secondary vacuum (<10 6 mBar) is produced in the reactor via a turbomolecular pump and is maintained for 2 hours. Once the desired secondary vacuum is obtained, the deposition is carried out.
Le dépôt d'une couche de chrome de 30 nm est obtenu en appliquant les paramètres suivants : The deposition of a 30 nm chromium layer is obtained by applying the following parameters:
Puissance RF : 120 W RF power: 120 W
Pression : 10 mTorr Pressure: 10 mTorr
Gaz :100 % argon Gas: 100% argon
Débit d'argon : 40 sccm Argon flow: 40 sccm
Tension d'autopolarisation de la cible : 650 V Target self-bias voltage: 650 V
Durée : 2 minutes Duration: 2 minutes
Etape 3 : dépôt de nanocristaux de diamant sur la surface du substrat (« nanoseeding » en anglais) (figure 6c) Step 3: deposit of diamond nanocrystals on the surface of the substrate (“nanoseeding” in English) (Figure 6c)
Le substrat recouvert d'une couche ultra mince de chrome est immergé dans une solution de chlorure de poly(diméthyl diallyl ammonium) diluée à 0,2 % en masse dans de l'eau ultra-pure pendant une durée de 15 minutes. The substrate covered with an ultra thin layer of chromium is immersed in a solution of poly (dimethyl diallyl ammonium chloride) diluted to 0.2% by mass in ultra-pure water for a period of 15 minutes.
Il est ensuite rincé à l'eau ultra-pure et immergé dans une solution aqueuse colloïdale de nanoparticules 15 de diamant possédant une charge de surface négative (0,05% en masse de nanodiamants de 5 nm de diamètre) pendant une durée de 30 minutes. Puis, l'échantillon est rincé à l'eau ultra-pure et séché sous flux d'azote. It is then rinsed with ultra-pure water and immersed in an aqueous colloidal solution of diamond nanoparticles having a negative surface charge (0.05% by mass of nanodiamonds 5 nm in diameter) for a period of 30 minutes . Then, the sample is rinsed with ultra-pure water and dried under nitrogen flow.
Etape 3 : croissance du diamant (figure 6d) Step 3: diamond growth (Figure 6d)
Le substrat recouvert d'une couche de chrome et de nanoparticules 15 de diamant est ensuite introduit dans un réacteur de croissance CVD assisté par plasma micro-onde à 2,45 GHz, réacteur MPCVD généralement utilisé pour faire croître des films de diamant. Le substrat est placé sur un porte-substrat et un masque (par exemple un masque en molybdène) peut être placé sur le substrat afin d'exclure de la croissance certaines faces du substrat. Un vide secondaire (<10 6 mBar) est réalisé via une pompe turbomoléculaire et est maintenu pendant 2 heures. The substrate covered with a layer of chromium and diamond nanoparticles is then introduced into a CVD growth reactor assisted by microwave plasma at 2.45 GHz, an MPCVD reactor generally used for growing diamond films. The substrate is placed on a substrate holder and a mask (for example a molybdenum mask) can be placed on the substrate in order to exclude from growth certain faces of the substrate. A secondary vacuum (<10 6 mBar) is produced via a turbomolecular pump and is maintained for 2 hours.
Puis, un mélange gazeux composé de dihydrogène et de méthane est injecté dans le réacteur MPCVD. La puissance micro-onde adéquate est appliquée et un plasma se forme au-dessus du porte-substrat. Pour obtenir une couche de diamant d'une épaisseur de 220 nm, ce qui donne une couleur interférentielle verte, les conditions expérimentales sont les suivantes : Then, a gaseous mixture composed of dihydrogen and methane is injected into the MPCVD reactor. Adequate microwave power is applied and a plasma is formed above the substrate holder. To obtain a diamond layer with a thickness of 220 nm, which gives a green interference color, the experimental conditions are as follows:
Pression : 35 mBar Pressure: 35 mBar
Puissance micro-onde appliquée : 950 W Applied microwave power: 950 W
Mélange gazeux : 0,6 % Vol. de dans H2 Gas mixture: 0.6% Vol. from in H2
Débit de gaz : 250 sccm Gas flow: 250 sccm
Température de l'échantillon : 750°C Sample temperature: 750 ° C
Durée de la synthèse : 1 heure Duration of the synthesis: 1 hour
Une photographie de la gemme composite 100 ainsi obtenue est présentée dans la figure 7. On peut voir qu'un disque coloré apparaît dans la face principale du diamant (face principale qui correspond à la table 2). A photograph of the composite gem 100 thus obtained is presented in FIG. 7. It can be seen that a colored disc appears in the main face of the diamond (main face which corresponds to table 2).
Les motifs réalisables, ainsi que les couleurs possibles sont multiples. The achievable patterns, as well as the possible colors are multiple.
On peut faire varier l'épaisseur de la couche enterrée pour faire apparaître un motif coloré ayant des zones plus « transparentes » que d'autres. Par exemple, dans la figure 8, on a un motif coloré, par exemple en vert, avec différents niveaux de transparences : un grand cercle clair englobant des éléments plus foncés (dont un plus petit cercle central, entouré de triangles). Cela peut être obtenu par un premier dépôt de chrome avec un masque ayant un trou du diamètre du cercle clair ; puis un deuxième dépôt avec un autre masque ayant un trou central entouré de triangles. Les éléments de la couche enterrée ayant une épaisseur plus importante dans les parties obtenues suite au deuxième dépôt sont les éléments apparaissant plus foncés. The thickness of the buried layer can be varied to reveal a colored pattern having more "transparent" areas than others. For example, in Figure 8, we have a colored pattern, for example in green, with different levels of transparency: a large light circle encompassing darker elements (including a smaller central circle, surrounded by triangles). This can be obtained by a first deposit of chromium with a mask having a hole of the diameter of the clear circle; then a second deposit with another mask having a central hole surrounded by triangles. The elements of the buried layer having a greater thickness in the parts obtained following the second deposition are the elements appearing darker.
On peut également créer via deux (ou plus) dépôts successifs CVD de diamant avec masquage ou un dépôt CVD diamant suivi d'une étape de gravure, différentes couleurs sur la face du diamant massif et ainsi créer des motifs multi-couleurs. Par exemple, dans la figure 9, on a un grand cercle, par exemple en violet foncé, et un plus petit cercle central, entouré de triangles, qui sont en vert foncé. Cela peut être obtenu en déposant une couche d'épaisseur uniforme sous forme de rond pour la couche enterré et recouvrir cette couche enterrée par une couche d'épaisseur variable pour la couche en diamant, les zones formées d'une épaisseur constante de couche enterrée et d'une première épaisseur de couche de diamant formant les zones en violet foncé et les zones formées d'une épaisseur constante de couche enterrée et d'une deuxième épaisseur de couche de diamant formant les zones en vert foncé. We can also create via two (or more) successive CVD diamond deposits with masking or a CVD diamond deposit followed by an etching step, different colors on the face of the solid diamond and thus create multi-color patterns. For example, in figure 9, we have a large circle, for example in dark purple, and a smaller central circle, surrounded by triangles, which are dark green. This can be obtained by depositing a layer of uniform thickness in the form of a circle for the buried layer and covering this buried layer with a layer of variable thickness for the diamond layer, the zones formed with a constant thickness of buried layer and a first thickness of diamond layer forming the zones in dark purple and the zones formed of a constant thickness of buried layer and a second thickness of diamond layer forming the zones in dark green.
On peut également combiner des variations de couleurs (variation de l'épaisseur de la couche diamant) avec des variations de transparence (variation d'épaisseur de la couche de métal), comme illustré dans la figure 10, où le grand rond est par exemple en violet clair et le petit rond central et les triangles sont en vert foncé. It is also possible to combine variations of colors (variation of the thickness of the diamond layer) with variations of transparency (variation of thickness of the metal layer), as illustrated in FIG. 10, where the large circle is for example in light purple and the small central circle and the triangles are in dark green.
Une fois la gemme composite obtenue (figure lia), on peut tout à fait récupérer le substrat diamant initial. La coloration du substrat diamant par le procédé selon l'invention présente en effet l'avantage d'être réversible. Once the composite gem has been obtained (Figure 11a), it is quite possible to recover the initial diamond substrate. The coloring of the diamond substrate by the method according to the invention has the advantage of being reversible.
Pour cela, on peut par exemple réaliser des micro-perforations 16 dans l'épaisseur de la couche de revêtement 11 en diamant jusqu'à atteindre la couche ultra- mince enterrée 12 (figure 11b). En choisissant un produit d'attaque chimique apte à attaquer le matériau de la couche ultra-mince sans attaquer le diamant massif 10, on peut récupérer le substrat 10 en diamant (figure 11c). Par exemple, si la couche enterrée est métallique, si l'on trempe la gemme composite dans un acide capable de dissoudre cette couche métallique, on récupérera la pierre précieuse intacte, car le diamant ne réagit pas avec l'acide. Cela permet d'effacer simplement un motif créé sur une pierre précieuse en diamant, sans altérer la pierre. For this, one can for example make micro-perforations 16 in the thickness of the diamond coating layer 11 until reaching the buried ultra-thin layer 12 (FIG. 11b). By choosing a chemical attack product capable of attacking the material of the ultra-thin layer without attacking the solid diamond 10, the diamond substrate 10 can be recovered (FIG. 11c). For example, if the buried layer is metallic, if we soak the composite gem in an acid capable of dissolving this metallic layer, we will recover the precious gemstone intact, because the diamond does not react with the acid. This allows you to simply erase a pattern created on a diamond gemstone, without altering the stone.

Claims

Revendications Claims
1. Gemme composite (100) comprenant : 1. Composite gem (100) comprising:
- un corps principal (10) en diamant, ayant au moins une face ; et - a main body (10) made of diamond, having at least one face; and
- une structure de coloration (13) de ladite face par interférence optique, comprenant une couche enterrée (12) semi-transparente ou opaque, ayant un indice de réfraction ni, qui est disposée sur la face du corps principal, et une couche de revêtement (11) en diamant, ayant un indice de réfraction n2, qui recouvre complètement la couche enterrée, ; - a coloring structure (13) of said face by optical interference, comprising a buried layer (12) semi-transparent or opaque, having a refractive index ni, which is arranged on the face of the main body, and a coating layer (11) in diamond, having a refractive index n2, which completely covers the buried layer,;
la différence entre ni et n2, en valeur absolue, étant supérieure ou égale à 0,1 ; et the difference between ni and n2, in absolute value, being greater than or equal to 0.1; and
la couche enterrée (12) étant apte à réfléchir un faisceau incident de lumière visible réfracté (22) par la couche de revêtement et la couche de revêtement (11) étant apte à fournir une coloration par interférence entre un faisceau incident de lumière visible réfléchi (21) par une surface externe de la couche de revêtement et un faisceau (24) réfracté par la couche de revêtement après réflexion sur la couche enterrée. the buried layer (12) being capable of reflecting an incident beam of refracted visible light (22) by the coating layer and the coating layer (11) being capable of providing coloring by interference between an incident beam of reflected visible light ( 21) by an external surface of the coating layer and a beam (24) refracted by the coating layer after reflection on the buried layer.
2. Gemme composite selon la revendication 1, dans laquelle la couche enterrée (12) présente une épaisseur supérieure ou égale à 5 nm. 2. Composite gem according to claim 1, in which the buried layer (12) has a thickness greater than or equal to 5 nm.
3. Gemme composite selon la revendication 1, dans laquelle la couche enterrée (12) présente une épaisseur comprise entre 5 et 100 nm, de préférence entre 5 et 50 nm. 3. A composite gem according to claim 1, in which the buried layer (12) has a thickness of between 5 and 100 nm, preferably between 5 and 50 nm.
4. Gemme composite selon l'une quelconque des revendications 1 à 3, dans laquelle la couche de revêtement (11) présente une épaisseur comprise entre 90 et 2000 nm, de préférence entre 100 et 1000 nm. 4. Composite gem according to any one of claims 1 to 3, wherein the coating layer (11) has a thickness between 90 and 2000 nm, preferably between 100 and 1000 nm.
5. Gemme composite selon l'une quelconque des revendications 1 à 4, dans laquelle la couche enterrée (12) est une couche métallique. 5. Composite gem according to any one of claims 1 to 4, in which the buried layer (12) is a metallic layer.
6. Gemme composite selon l'une quelconque des revendications 1 à 5, dans laquelle la couche enterrée (12) présente une épaisseur variable. 6. Composite gem according to any one of claims 1 to 5, wherein the buried layer (12) has a variable thickness.
7. Gemme composite selon l'une quelconque des revendications 1 à 6, dans laquelle la couche de revêtement (11) présente une épaisseur variable. 7. Composite gem according to any one of claims 1 to 6, in which the coating layer (11) has a variable thickness.
8. Procédé de fabrication d'une gemme composite telle que définie dans l'une quelconque des revendications 1 à 7, comprenant les étapes suivantes : 8. A method of manufacturing a composite gem as defined in any one of claims 1 to 7, comprising the following steps:
- la fourniture du corps principal (10) en diamant ayant au moins une face ; - the supply of the main body (10) in diamond having at least one face;
- la formation de la couche enterrée (12) sur ladite au moins une face, par exemple par dépôt physique en phase vapeur ; - The formation of the buried layer (12) on said at least one face, for example by physical vapor deposition;
- la formation de la couche de revêtement (11) en diamant, de manière à recouvrir la couche enterrée. - the formation of the diamond coating layer (11), so as to cover the buried layer.
9. Procédé de fabrication selon la revendication 8, dans lequel la formation de la couche enterrée comprend au moins deux dépôts successifs du matériau de la couche enterrée, réalisés par lithographie et/ou avec des masques différents. 9. The manufacturing method according to claim 8, wherein the formation of the buried layer comprises at least two successive deposits of the material of the buried layer, produced by lithography and / or with different masks.
10. Procédé de fabrication selon la revendication 8 ou la revendication 9, dans lequel la formation de la couche de revêtement comprend une opération choisie parmi : 10. The manufacturing method according to claim 8 or claim 9, in which the formation of the coating layer comprises an operation chosen from:
- au moins deux dépôts successifs du matériau diamant de la couche de revêtement, par exemple par dépôt chimique en phase vapeur, réalisés avec des masques différents ; et - At least two successive deposits of the diamond material of the coating layer, for example by chemical vapor deposition, carried out with different masks; and
- un dépôt d'une couche diamant, par exemple par dépôt chimique en phase vapeur, suivi d'une gravure de ladite couche. a deposition of a diamond layer, for example by chemical vapor deposition, followed by etching of said layer.
11. Procédé pour récupérer le corps principal (10) d'une gemme composite (100) obtenue selon le procédé de fabrication tel que défini dans l'une quelconque des revendications 8 à 10, comprenant les étapes successives suivantes : 11. Method for recovering the main body (10) of a composite gem (100) obtained according to the manufacturing process as defined in any one of claims 8 to 10, comprising the following successive steps:
- la réalisation d'ouvertures (16) dans l'épaisseur de la couche de revêtement (11) jusqu'à atteindre la couche enterrée (12) ; - The realization of openings (16) in the thickness of the coating layer (11) until reaching the buried layer (12);
- la dissolution de la couche enterrée à l'aide d'un agent d'attaque chimique choisi pour obtenir une attaque sélective de la couche enterrée, de manière à détacher le corps principal de la couche de revêtement ; - Dissolving the buried layer using a chemical attack agent chosen to obtain a selective attack on the buried layer, so as to detach the main body from the coating layer;
- un éventuel polissage de la face du corps principal pour supprimer des traces de la couche de revêtement. - possible polishing of the face of the main body to remove traces of the coating layer.
PCT/FR2019/053165 2018-12-28 2019-12-18 Colouring by optical interference of a diamond WO2020136327A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19800250A1 (en) * 1997-01-13 1998-08-06 Winter Cvd Technik Gmbh Grinding disc for optical lenses, fine stones, marble, wood, metal, plastics etc.
US20050069709A1 (en) * 2003-09-29 2005-03-31 Lev Leonid C. Diamond coated article and method of its production
WO2010009467A2 (en) * 2008-07-18 2010-01-21 Serenity Technologies, Inc. Method for producing nanocrystalline diamond coatings on gemstones and other substrates
WO2011064446A1 (en) * 2009-11-30 2011-06-03 Beneq Oy Method for forming a decorative coating on a gemstone, a decorative coating on a gemstone, and uses of the same
EP3178971A1 (en) * 2014-08-08 2017-06-14 Sumitomo Electric Industries, Ltd. Method for manufacturing diamond, diamond, diamond composite substrate, diamond bonded substrate, and tool

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19800250A1 (en) * 1997-01-13 1998-08-06 Winter Cvd Technik Gmbh Grinding disc for optical lenses, fine stones, marble, wood, metal, plastics etc.
US20050069709A1 (en) * 2003-09-29 2005-03-31 Lev Leonid C. Diamond coated article and method of its production
WO2010009467A2 (en) * 2008-07-18 2010-01-21 Serenity Technologies, Inc. Method for producing nanocrystalline diamond coatings on gemstones and other substrates
WO2011064446A1 (en) * 2009-11-30 2011-06-03 Beneq Oy Method for forming a decorative coating on a gemstone, a decorative coating on a gemstone, and uses of the same
EP3178971A1 (en) * 2014-08-08 2017-06-14 Sumitomo Electric Industries, Ltd. Method for manufacturing diamond, diamond, diamond composite substrate, diamond bonded substrate, and tool

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