CN115506025A - Hole type SrTiO 3 Material, preparation method and application thereof - Google Patents
Hole type SrTiO 3 Material, preparation method and application thereof Download PDFInfo
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- 239000000463 material Substances 0.000 title claims abstract description 137
- 229910002367 SrTiO Inorganic materials 0.000 title claims abstract description 102
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 22
- 238000000137 annealing Methods 0.000 claims abstract description 11
- 238000007872 degassing Methods 0.000 claims abstract description 11
- 238000010438 heat treatment Methods 0.000 claims description 59
- 239000000758 substrate Substances 0.000 claims description 21
- 230000008020 evaporation Effects 0.000 claims description 13
- 238000001704 evaporation Methods 0.000 claims description 13
- 239000010409 thin film Substances 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 11
- 238000004381 surface treatment Methods 0.000 abstract 1
- 239000013078 crystal Substances 0.000 description 19
- 150000002500 ions Chemical class 0.000 description 13
- 238000001451 molecular beam epitaxy Methods 0.000 description 12
- 238000012360 testing method Methods 0.000 description 12
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 10
- 239000001301 oxygen Substances 0.000 description 10
- 229910052760 oxygen Inorganic materials 0.000 description 10
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 9
- 230000008859 change Effects 0.000 description 6
- 239000010408 film Substances 0.000 description 5
- 229910021645 metal ion Inorganic materials 0.000 description 5
- 230000007704 transition Effects 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 239000003337 fertilizer Substances 0.000 description 3
- 239000003574 free electron Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000004519 grease Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000002310 reflectometry Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 150000001768 cations Chemical class 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000012876 topography Methods 0.000 description 2
- 229910003077 Ti−O Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009832 plasma treatment Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/16—Oxides
- C30B29/22—Complex oxides
- C30B29/32—Titanates; Germanates; Molybdates; Tungstates
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- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B31/00—Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor
- C30B31/06—Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor by contacting with diffusion material in the gaseous state
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Abstract
The invention discloses a hole type SrTiO 3 A material, a preparation method and application thereof. The preparation method comprises the following steps: n-type doped SrTiO under vacuum condition 3 Degassing the material; se for degassed n-type doped SrTiO 3 Carrying out surface treatment on the material to form an atomically flat reconstructed surface; removal of n-doped SrTiO 3 Se on the surface of the material, and SrTiO doped with Sr to n type 3 The material is treated to obtain p-type doped SrTiO 3 A material. The embodiment of the invention provides a hole type SrTiO 3 Of materialsThe preparation method has simple process flow, and the obtained hole type doped material has better high-temperature stability and provides conditions for subsequent high-temperature growth and sample annealing.
Description
Technical Field
The invention particularly relates to a hole type SrTiO 3 A material, a preparation method and application thereof, belonging to the technical field of micro-nano manufacturing.
Background
Strontium titanate (SrTiO) 3 STO for short), is a typical perovskite structure material, has better lattice matching degree with a plurality of high-temperature superconducting materials, and has the advantages of high dielectric constant, low dielectric loss, good thermal stability and the like; meanwhile, the STO has a higher band gap width as a functional material, so that the STO is the most widely used substrate material at present in the field of growth of high-temperature superconducting films; however, STO also has disadvantages: the energy gap of 3.2eV makes STO an insulating material at room temperature, a property that limits its application in many fields. To overcome this drawback, attempts have been made to modify the STO by doping.
The ideal STO crystal belongs to a cubic crystal system and is a space group Pm3m. In STO, the cation Sr with the larger radius 2+ The cation Ti occupying 8 vertex positions of the cubic unit cell and having a smaller radius 4+ At the body center of the unit cell, anion O 2- Is located in the center of the face. When the impurity ions enter the STO material, if the ionic radius and electronegativity of the impurity ions are equal to Sr 2+ And Ti 4+ Close then these impurity ions may be in the apical position (Sr) 2+ ) Or body center position (Ti) 4+ ) Substitution occurs.
The metal ion doping can be divided into n-type doping and p-type doping, wherein the n-type doping means that the number of electrons of the substituted ions is larger than that of the substituted ions, the substituted ions enter a unit cell, redundant electrons are released, and ionized immovable positive charge centers are formed; such as Pr for Sr and Nb for Ti. There are two main theories on the doping of STO n-type at present: one is the electrovalence compensation theory, which considers that the free electrons generated by the substitution of the high valence ions are replaced by Ti 4+ Trapped to form Ti 4+ .e - (ii) a The second is oxygen volatilization theory, which considers that the doping of high valence ions causes Sr vacancy V Sr Sr vacancy weakens adjacent Ti-O chemical bond, promotes volatilization of crystal oxygen, forms oxygen vacancy, ionizes oxygen vacancy to generate free electrons, and when the number of doping ions is larger, oxygen volatilization theory plays a leading role, and n-type doping can easily improve the electrical conductivity of STO from semiconductor to 10 -4 Omega cm, up to the metal range.
p-type doping often incorporates a small amount of metal ions with atomic radius close to that of Ti or Sr, whose atomic valence is not easily changed, into STO, and the incorporated metal ions need to satisfy the condition that the number of electrons is smaller than that of the substituted ions. According to the requirements of similar ionic radius and electronegativity, the general Ag + 、Ni + 、Li + 、Mn 2+ 、Zn 2+ Etc. may replace the Sr position; fe 3+ 、Al 3+ 、Cu 2+ Etc. will replace the Ti site. These substitutional ions form an effective p-type doping in the STO.
Most of the STO materials commercially available at present are Nb-doped and n-type doped, and the STO (100) material doped with n-type is generally processed by heating to 1000 ℃ with direct current and maintaining for 1h, so as to obtain the conductive material and the atomically flat step required for film growth, the STO processing method is heat treatment under a non-oxygen atmosphere, and the processing condition can make oxygen in the STO escape to form 1 oxygen vacancy and 2 free electrons, and the reaction equation is as follows:
electrons are free to move between different Ti ions, which results in dielectric loss and leakage current, and thus, in practical applications, the intrinsic STO is also treated by p-type doping.
Currently, the commonly used p-type is doped with Fe 3+ 、Mn 2+ When metal ions are subjected to plasma treatment, electrons in the doped STO can move to a heterojunction interface and are captured by the doped metal ions, a space charge region, namely a PN junction, is formed at the interface, the STO is changed into hole doping, and the Fermi surface moves to a low-energy level, so that the problems of dielectric loss and leakage current of the STO are effectively solved.
As described above, it is necessary to perform effective p-type doping of the STO single crystal, regardless of whether the surface properties of the STO itself or the relationship between the STO as a substrate and an epitaxially grown thin film are studied, although Fe is used 3+ Good results can be obtained by p-type doping of STO by plasma ions, but in molecular beam epitaxy, STO is one of the most commonly used substrates, and the substrate is generally required to be heated to a high temperature, but as the temperature of the STO substrate increases, because of Fe 3+ The oxygen vacancy formed by doping is disabled, and the resistance change of the STO is closely related to the migration of the oxygen vacancy.
Disclosure of Invention
The invention mainly aims to provide a hole type SrTiO 3 The material, the preparation method and the application thereof, so as to overcome the defects in the prior art.
In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:
the embodiment of the invention provides a hole type SrTiO 3 A method of preparing a material comprising:
(1) N-type doped SrTiO under vacuum condition 3 Degassing the material;
(2) The SrTiO treated in the step (1) is treated 3 Se treatment is carried out on the material to form an atomically flat reconstructed surface;
(3) Subjecting the SrTiO treated in the step (2) to 3 The material is subjected to Sr treatment to obtain p-type SrTiO 3 A material.
Practice of the inventionThe example also provides a hole type SrTiO 3 The preparation method of the material specifically comprises the following steps:
(1) Doping n-type SrTiO 3 Placing the material in an ultra-vacuum chamber, and adjusting the vacuum degree in the ultra-vacuum chamber to be higher than 5 × 10 -9 mbar, and heating the SrTiO by direct current 3 Heating the material to 500-700 deg.C for 20-40min to remove said SrTiO 3 Molecules adsorbed on the surface of the material;
(2) Heating the SrTiO treated in the step (1) in a direct current heating mode 3 Heating the material to 1000-1100 deg.C, maintaining for 10-20min, forming Se atmosphere in the ultra-vacuum chamber, and maintaining for 20-40min to obtain SrTiO material 3 Se treatment of the material, wherein after the Se treatment is finished, the vacuum degree in the super-vacuum cavity is adjusted to 1 multiplied by 10 -9 mbar or above, and at 1000-1100 deg.C 3 Annealing the material for 10-30min to remove the SrTiO 3 Se is adsorbed on the surface of the material, so that an atomic-level flat reconstructed surface is formed;
(3) Heating the SrTiO treated in the step (2) in a direct current heating mode 3 Heating the material to 900-1000 ℃, forming Sr atmosphere in an ultra-vacuum cavity and keeping for 3-10min to realize the preparation of the SrTiO 3 Sr treatment of the material to obtain p-type doped SrTiO 3 A material.
The embodiment of the invention also provides the hole type SrTiO obtained by the preparation method 3 A material.
The embodiment of the invention also provides a growth method of the high-temperature superconducting film, which comprises the following steps: adopting the hole type SrTiO 3 The material is used as a substrate, and a high-temperature superconducting thin film is grown on the substrate.
Compared with the prior art, the embodiment of the invention provides the hole type SrTiO 3 The preparation method of the material has simple process flow, and the obtained hole type doped material has better high-temperature stability and provides conditions for subsequent high-temperature growth and sample annealing.
Drawings
FIG. 1 is a schematic diagram of an exemplary embodiment of the present inventionA hole type SrTiO is provided 3 Schematic flow diagram of the material preparation method.
FIG. 2 is a graphical representation of the surface STM topography of Sr-treated p-type STO material obtained in an exemplary embodiment of the present invention;
FIG. 3 is an R-T curve for n-type STO material and p-type STO material before and after Sr treatment in an exemplary embodiment of the present invention;
FIG. 4 is a temperature change curve for Hall testing of n-type STO material and p-type STO material before and after Sr treatment in an exemplary embodiment of the present invention:
fig. 5 is a representation of the STS test for a FeTe thin film grown on Sr-treated p-type STO material in an exemplary embodiment of the invention.
Detailed Description
In view of the deficiencies in the prior art, the inventors of the present invention have made extensive studies and extensive practices to provide technical solutions of the present invention. The technical solution, its implementation and principles, etc. will be further explained as follows.
The embodiment of the invention provides a hole type SrTiO 3 A method of preparing a material comprising:
(1) N-type doped SrTiO under vacuum condition 3 Degassing the material;
(2) The SrTiO treated in the step (1) is treated 3 Se treatment is carried out on the material to form an atomically flat reconstructed surface;
(3) The SrTiO treated in the step (2) 3 The material is subjected to Sr treatment to obtain p-type SrTiO 3 A material.
Further, the step (1) specifically comprises: n-type doped SrTiO in vacuum condition 3 Heating the material to 500-700 deg.C for 20-40min to remove n-doped SrTiO 3 The molecules adsorbed on the surface of the material obtain a clean surface.
Further, the step (1) specifically comprises: at 1X 10 -9 mbar-9×10 -9 N-type doped SrTiO under vacuum condition of mbar 3 The material is degassed.
Further, the step (2) specifically comprises: will be subjected to the step(1) The treated SrTiO 3 Heating the material to 1000-1100 ℃, keeping the temperature for 10-20min, and then heating the SrTiO in Se atmosphere 3 The material is subjected to Se treatment, and after the Se treatment is finished, annealing is further carried out in ultrahigh vacuum at 1000-1100 ℃ so as to remove the SrTiO 3 Se is adsorbed on the surface of the material, so that an atomically flat reconstructed surface is formed.
Further, the Se treatment time is 20-40min.
Further, the step (2) further comprises: and (3) heating the Se evaporation source to 110-130 ℃ by means of a molecular beam epitaxial growth system to form the Se atmosphere.
Further, the degree of vacuum of the ultra-high vacuum is 5 × 10 -10 mbar-5×10 -9 mbar。
Further, the step (3) specifically comprises: the SrTiO treated in the step (2) is treated 3 The temperature of the material is adjusted to 900-1000 ℃, and SrTiO is treated under the Sr atmosphere condition 3 The Sr treatment is carried out on the material, thereby obtaining the p-type doped SrTiO 3 A material.
Further, the step (3) further comprises: heating the Sr evaporation source to 200-250 ℃ by means of a molecular beam epitaxial growth system to form the Sr atmosphere.
The embodiment of the invention also provides a hole type SrTiO 3 The preparation method of the material specifically comprises the following steps:
(1) Doping n-type SrTiO 3 Placing the material in an ultra-vacuum chamber, and adjusting the vacuum degree in the ultra-vacuum chamber to 1 × 10 -9 mbar-9×10 -9 mbar, and heating the SrTiO by direct current 3 Heating the material to 500-700 deg.C for 20-40min to remove said SrTiO 3 Molecules adsorbed on the surface of the material;
(2) Heating the SrTiO treated in the step (1) in a direct current heating mode 3 Heating the material to 1000-1100 deg.C, maintaining for 10-20min, forming Se atmosphere in the super-vacuum chamber, and maintaining for 20-40min to realize the SrTiO 3 Se treatment of a material wherein the concentration of Se atmosphere at the time of Se treatment depends on the heating temperature and time of Se source, preferredThe heating temperature of the Se source is 100-150 ℃, and the heating time is 20-40min;
and after the Se treatment is finished, adjusting the vacuum degree in the super-vacuum chamber to 5 x 10 -10 mbar-5×10 -9 mbar in the presence of SrTiO at 1000-1100 deg.C 3 Annealing the material for 10-30min to remove the SrTiO 3 Se is adsorbed on the surface of the material, so that an atomic-level flat reconstructed surface is formed;
(3) Heating the SrTiO treated in the step (2) in a direct current heating mode 3 Heating the material to 900-1000 ℃, forming Sr atmosphere in an ultra-vacuum chamber and keeping for 3-10min to realize the SrTiO 3 Sr treatment of the material to obtain p-type doped SrTiO 3 The Sr atmosphere concentration during Sr treatment depends on the heating temperature and time of an Sr source, the heating temperature of the Sr source is 200-250 ℃, and the heating time is 3-10min; and after the Sr treatment is finished, the temperature of the Sr source is reduced.
The embodiment of the invention also provides the hole type SrTiO obtained by the preparation method 3 A material.
The embodiment of the invention also provides a growth method of the high-temperature superconducting film, which comprises the following steps: adopting the hole type SrTiO 3 The material is used as a substrate, and a high-temperature superconducting thin film is grown on the substrate.
The embodiments, implementations, principles, and so on of the present invention will be further explained with reference to the drawings, and unless otherwise indicated, the methods and systems for molecular beam epitaxy according to the embodiments of the present invention are well known to those skilled in the art.
Example 1
Referring to fig. 1, in some more specific embodiments, a commercially available STO material (i.e., n-type doped SrTiO) 3 Material SrTiO doped with Nb in this example 3 Single crystal (100) as an example) process for forming a high temperature stable p-type material includes the steps of:
s1, sample loading: wearing dust-free gloves, wearing a mask, and cleaning the tweezers and the sample rack with alcohol; commercial use of tweezers to orient in the (100) directionNb doped SrTiO of 3 Fixing a single crystal (100) (with the size of 10 x 2 x 0.5mm, purchased from combined fertilizer crystal materials Co., ltd., hereinafter referred to as a sample) in the middle of a direct current sample rack (which can be purchased as an existing sample rack) to ensure that the sample rack and the sample are not polluted by dust, grease and the like, respectively measuring the resistance at two ends of the sample by using a universal meter after the sample is loaded, and determining that the resistance is basically consistent;
s2, degassing: transferring the sample into an ultrahigh vacuum chamber equipped with a DC heating stage and an infrared thermometer, setting the emission coefficient of the infrared thermometer to 0.8 (according to the query data, the heat reflectivity of STO single crystal is 0.8, and the emission coefficient of the infrared thermometer is 0.8, so as to observe the temperature of STO single crystal at any time, fine-tune the current, observe the vacuum degree change in the ultrahigh vacuum chamber), and maintain the vacuum degree to 1 × 10 -9 mbar, heating the sample to 500 ℃ by adopting a direct current heating mode, keeping the temperature for 40min to fully degas, and basically completely desorbing water molecules, gas molecules and the like adsorbed in the atmosphere on the surface of the sample after the degassing is finished so as to obtain a clean surface;
s3, se treatment: slowly increasing the current, still adopting a direct current heating mode to heat the sample to 1000 ℃, and keeping the temperature for 20min; heating a Se evaporation source to 100 ℃ by adopting a molecular beam epitaxy growth (MBE) system to obtain Se atmosphere, and keeping the Se atmosphere for 40min to realize the aim of adjusting the temperature of the SrTiO 3 Se treatment of the material;
after the Se evaporation source is turned off, the vacuum degree in the ultrahigh vacuum cavity is adjusted to be 5 multiplied by 10 -10 mbar, annealing the sample at 1000 ℃ for 30min to remove Se adsorbed on the surface of the sample, wherein in the process, se treatment enables atoms on the surface of the sample to be sufficiently migrated to form an atomically flat reconstructed surface;
s4, sr treatment: after Se treatment is finished, current is finely adjusted, a sample is heated to 900 ℃ by adopting a direct current heating mode, a Sr evaporation source is heated to 200 ℃ by adopting a Molecular Beam Epitaxy (MBE) system, a Sr atmosphere is obtained and kept for 10min, and the SrTiO is subjected to 3 Sr treatment of the material, thereby obtaining a p-type STO (100) material;
and S5, taking the p-type STO (100) material as a substrate, and growing a FeTe thin film on the p-type STO (100) substrate, wherein the growth conditions of the FeTe thin film can adopt process parameters known by a person skilled in the art.
The obtained p-type STO (100) material is subjected to STM and transport tests, the test results are respectively shown in FIGS. 2-4, the hole conductivity of the Sr-treated STO is only shown at low temperature, so all the tested data are also obtained by testing at the temperature of liquid helium, wherein the scanning conditions of the STM test are as follows: 1.5V,50pA, 500X 500nm 2 FIG. 2 shows the surface STM topography of the p-type STO material after Sr treatment, and it can be seen from FIG. 2 that the surface of the p-type STO material has steps and is atomically flat; FIG. 3 is an R-T curve for n-type STO material and p-type STO material before and after Sr treatment: the curve of FIG. 3 shows that the STO treated by Sr has obvious resistance upwarping phenomenon at low temperature, the inset is detail enlargement of the transition part, and the transition temperature is Tf-145K; FIG. 4 is the Hall test temperature change curves of n-type STO material and p-type STO material before and after Sr treatment: it can be seen that the Sr treatment STO undergoes a transition from n-type conductivity (negative slope) to p-type conductivity (positive slope) at low temperatures, with the inset being an enlargement of the transition; therefore, the invention adopts Sr to treat the commercial STO material, and can obtain the hole type doping material with high-temperature stability.
When the STO is treated by Sr, the temperature of the STO is as high as 900-1000 ℃, a film grown on the STO subsequently cannot be heated to the high temperature, and Sr treated by Sr can stably exist on an STO substrate and form thermal stable hole doping; for example, when an FeTe thin film is grown on an Sr-treated STO substrate, the temperature of the STO substrate is about 300 ℃. Fig. 5 is a graph showing STS test of a FeTe thin film grown on a p-type STO material after Sr treatment, and it can be seen from the graph in fig. 5 that the FeTe grown after Sr treatment STO can have a significant forward direction shift, which shows that the Sr-STO substrate can still provide hole doping to the FeTe thin film after being heated, thereby demonstrating that the Sr-STO substrate obtained by the embodiment of the present invention has good thermal stability.
Example 2
Referring to fig. 1, in some more specific embodiments, a commercially available STO material (i.e., n-type doped SrTiO) 3 Materials, the present embodimentFor example SrTiO doped with Nb 3 Single crystal (100) as an example) process for forming a high temperature stable p-type material includes the steps of:
s1, sample loading: wearing dust-free gloves, wearing a mask, and cleaning the tweezers and the sample rack by using alcohol; commercial Nb-doped SrTiO with tweezers oriented in the (100) direction 3 Fixing a single crystal (100) (with the size of 10 x 2 x 0.5mm, purchased from combined fertilizer crystal materials limited, hereinafter referred to as a sample) in the middle of a direct current sample rack (shown in figure 2), ensuring that the sample rack and the sample are not polluted by dust, grease and the like, respectively measuring the resistances of two ends of the sample by using a universal meter after the sample is loaded, and determining that the resistances are basically consistent;
s2, degassing: transferring the sample into an ultrahigh vacuum chamber equipped with a DC heating stage and an infrared thermometer, setting the emission coefficient of the infrared thermometer to 0.8 (according to the query data, the heat reflectivity of STO single crystal is 0.8, and the emission coefficient of the infrared thermometer is 0.8, so as to observe the temperature of STO single crystal at any time, fine-tune the current, observe the vacuum degree change in the ultrahigh vacuum chamber), and maintain the vacuum degree at 5 × 10 -9 mbar, heating the sample to 700 ℃ by adopting a direct current heating mode, keeping for 20min to fully degas, and basically completely desorbing water molecules, gas molecules and the like adsorbed in the atmosphere on the surface of the sample after the degassing is finished so as to obtain a clean surface;
s3, se treatment: slowly increasing the current, still adopting a direct current heating mode to heat the sample to 1100 ℃, and keeping for 10min; heating a Se evaporation source to 150 ℃ by adopting a molecular beam epitaxy growth (MBE) system to obtain Se atmosphere, and keeping the Se atmosphere for 20min to realize the aim of adjusting the temperature of the SrTiO 3 Se treatment of the material;
after the Se evaporation source is turned off, the vacuum degree in the ultrahigh vacuum cavity is adjusted to be 3 multiplied by 10 -9 mbar, annealing the sample at 1100 ℃ for 10min to remove Se adsorbed on the surface of the sample, wherein in the process, se treatment enables atoms on the surface of the sample to be sufficiently migrated to form an atomically flat reconstructed surface;
s4, sr treatment: after Se treatment is finished, current is finely adjusted, and a direct current heating mode is adopted to heat the sample toHeating the Sr evaporation source to 250 ℃ by adopting a molecular beam epitaxy growth (MBE) system at 1000 ℃, obtaining Sr atmosphere and keeping the Sr atmosphere for 3min, thereby realizing the SrTiO 3 Sr treatment of the material to obtain p-type STO (100) material.
STM and transport tests are carried out on the obtained p-type STO (100) material, and the test results are basically consistent with those of example 1.
Example 3
Referring to fig. 1, in some more specific embodiments, a commercially available STO material (i.e., n-type doped SrTiO) 3 Material SrTiO doped with Nb in this example 3 Single crystal (100) as an example) process for forming a high temperature stable p-type material includes the steps of:
s1, sample loading: wearing dust-free gloves, wearing a mask, and cleaning the tweezers and the sample rack with alcohol; commercial Nb-doped SrTiO with tweezers oriented in the (100) direction 3 Fixing a single crystal (100) (with the size of 10 x 2 x 0.5mm, purchased from combined fertilizer crystal materials limited, hereinafter referred to as a sample) in the middle of a direct current sample rack (shown in figure 2), ensuring that the sample rack and the sample are not polluted by dust, grease and the like, respectively measuring the resistances of two ends of the sample by using a universal meter after the sample is loaded, and determining that the resistances are basically consistent;
s2, degassing: transferring the sample into an ultrahigh vacuum chamber equipped with a DC heating stage and an infrared thermometer, setting the emission coefficient on the infrared thermometer to 0.8 (according to the query data, the heat reflectivity of the STO single crystal is 0.8, and the emission coefficient on the infrared thermometer is 0.8, so as to observe the temperature of the STO single crystal at any time, finely adjust the current, observe the change of the vacuum degree in the ultrahigh vacuum chamber), and maintain the vacuum degree at 9 × 10 -9 mbar, heating the sample to 650 ℃ by adopting a direct current heating mode, keeping for 30min to fully degas, and basically completely desorbing water molecules, gas molecules and the like adsorbed in the atmosphere on the surface of the sample after the degassing is finished so as to obtain a clean surface;
s3, se treatment: slowly increasing current, heating the sample to 1070 deg.C by direct current heating method, and maintaining for 14min; then a molecular beam epitaxy growth (MBE) system is adopted to heat the Se evaporation source to 125 DEG CObtaining Se atmosphere and keeping for 26min to realize the aim of controlling the SrTiO 3 Se treatment of the material;
after the Se evaporation source is turned off, the vacuum degree in the ultrahigh vacuum cavity is adjusted to be 5 multiplied by 10 -9 mbar, and annealing the sample at 1060 ℃ for 13min to remove Se adsorbed on the surface of the sample, wherein in the process, se treatment enables atoms on the surface of the sample to be sufficiently migrated, and an atomically flat reconstructed surface is formed;
s4, sr treatment: after Se treatment is finished, current is finely adjusted, a sample is heated to 960 ℃ by adopting a direct current heating mode, an Sr evaporation source is heated to 230 ℃ by adopting a Molecular Beam Epitaxy (MBE) system, an Sr atmosphere is obtained and kept for 7min, and the SrTiO is subjected to 3 Sr treatment of the material to obtain p-type STO (100) material.
STM and transport tests are carried out on the obtained p-type STO (100) material, and the test result is basically consistent with that of the example 1.
The embodiment of the invention provides a hole type SrTiO 3 The preparation method of the material has simple process flow, and the obtained hole type doped material has better high-temperature stability and provides conditions for subsequent high-temperature growth and sample annealing.
The embodiment of the invention provides a hole type SrTiO 3 In the preparation method of the material, sr treatment is adopted to prepare SrTiO 3 The substrate provides hole doping due to the Sr doping process, srTiO 3 The material is in a high-temperature environment of 900-1000 ℃, so that the obtained material has good high-temperature stability, and the problem of substrate failure cannot be caused when the substrate is heated later (the temperature is less than the Sr treatment temperature).
It should be understood that the above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and therefore, the protection scope of the present invention is not limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered in the protection scope of the present invention.
Claims (10)
1. CavityForm SrTiO 3 The preparation method of the material is characterized by comprising the following steps:
(1) N-type doped SrTiO under vacuum condition 3 Degassing the material;
(2) The SrTiO treated in the step (1) is treated 3 Se treatment is carried out on the material to form an atomically flat reconstructed surface;
(3) The SrTiO treated in the step (2) 3 The material is subjected to Sr treatment to obtain p-type SrTiO 3 A material.
2. The method according to claim 1, wherein the step (1) specifically comprises: n-type doped SrTiO under vacuum condition 3 Heating the material to 500-700 deg.C for 20-40min to remove n-doped SrTiO 3 The molecules adsorbed on the surface of the material obtain a clean surface.
3. The preparation method according to claim 2, wherein the step (1) specifically comprises: at 1X 10 -9 mbar-9×10 -9 SrTiO doped with n type under mbar vacuum degree condition 3 Degassing the material; .
4. The preparation method according to claim 1, wherein the step (2) specifically comprises: the SrTiO treated in the step (1) is treated 3 Heating the material to 1000-1100 ℃, and subjecting the SrTiO to Se atmosphere 3 The material is subjected to Se treatment, and after the Se treatment is finished, annealing is further carried out in ultrahigh vacuum at 1000-1100 ℃ so as to remove the SrTiO 3 Se adsorbed on the surface of the material so as to form an atomically flat reconstructed surface;
preferably, the Se treatment time is 20-40min.
5. The method of claim 4, wherein step (2) further comprises: heating a Se evaporation source to 110-130 ℃ by means of a molecular beam epitaxial growth system to form the Se atmosphere;
and/orThe vacuum degree of the ultra-high vacuum is 5 multiplied by 10 -10 mbar-5×10 -9 mbar。
6. The method according to claim 1, wherein the step (3) specifically comprises: the SrTiO treated in the step (2) is treated 3 The temperature of the material is adjusted to 900-1000 ℃, and SrTiO is treated under the Sr atmosphere condition 3 The material is subjected to said Sr treatment, thereby obtaining P-type doped SrTiO 3 A material.
7. The method of claim 6, wherein the step (3) further comprises: heating the Sr evaporation source to 200-250 ℃ by means of a molecular beam epitaxial growth system to form the Sr atmosphere.
8. Hole type SrTiO 3 The preparation method of the material is characterized by comprising the following steps:
(1) Doping n-type SrTiO 3 Placing the material in an ultra-vacuum chamber, and adjusting the vacuum degree in the ultra-vacuum chamber to be higher than 5 × 10 -9 mbar, and heating the SrTiO by direct current 3 Heating the material to 500-700 deg.C for 20-40min to remove said SrTiO 3 Molecules adsorbed on the surface of the material;
(2) Heating the SrTiO treated in the step (1) in a direct current heating mode 3 Heating the material to 1000-1100 deg.C, maintaining for 10-20min, forming Se atmosphere in the ultra-vacuum chamber, and maintaining for 20-40min to obtain SrTiO material 3 Se treatment of the material, wherein after the Se treatment is finished, the vacuum degree in the super-vacuum cavity is adjusted to 1 multiplied by 10 -9 mbar or more, and at 1000-1100 deg.C 3 Annealing the material for 10-30min to remove the SrTiO 3 Se adsorbed on the surface of the material so as to form an atomically flat reconstructed surface;
(3) Heating the SrTiO treated in the step (2) in a direct current heating mode 3 Heating the material to 900-1000 ℃, forming Sr atmosphere in an ultra-vacuum chamber and keeping for 3-10min to realize the SrTiO 3 Sr position of materialThus obtaining p-type doped SrTiO 3 A material.
9. The cavitated SrTiO obtained by the production method according to any one of claims 1 to 7 or claim 8 3 A material.
10. A method for growing a high-temperature superconducting thin film is characterized by comprising the following steps: the use of the hole type SrTiO of claim 9 3 The material is used as a substrate, and a high-temperature superconducting thin film is grown on the substrate.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1303958A (en) * | 1999-11-24 | 2001-07-18 | 中国科学院物理研究所 | Indium-doped strontium titanate material and preparation method thereof |
| JP2008239456A (en) * | 2007-03-29 | 2008-10-09 | Shimane Univ | Functional strontium titanate crystal, and method of producing the same |
| CN104947192A (en) * | 2015-05-25 | 2015-09-30 | 中国科学院上海微***与信息技术研究所 | Preparation method of perovskite type SrIrO3 single crystal film material |
| CN105161217A (en) * | 2015-07-07 | 2015-12-16 | 中国科学院上海微***与信息技术研究所 | Perovskite type Sr2IrO4 monocrystalline thin film material preparation method |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1303958A (en) * | 1999-11-24 | 2001-07-18 | 中国科学院物理研究所 | Indium-doped strontium titanate material and preparation method thereof |
| JP2008239456A (en) * | 2007-03-29 | 2008-10-09 | Shimane Univ | Functional strontium titanate crystal, and method of producing the same |
| CN104947192A (en) * | 2015-05-25 | 2015-09-30 | 中国科学院上海微***与信息技术研究所 | Preparation method of perovskite type SrIrO3 single crystal film material |
| CN105161217A (en) * | 2015-07-07 | 2015-12-16 | 中国科学院上海微***与信息技术研究所 | Perovskite type Sr2IrO4 monocrystalline thin film material preparation method |
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