US2946753A - Ferromagnetic material - Google Patents

Ferromagnetic material Download PDF

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US2946753A
US2946753A US603136A US60313656A US2946753A US 2946753 A US2946753 A US 2946753A US 603136 A US603136 A US 603136A US 60313656 A US60313656 A US 60313656A US 2946753 A US2946753 A US 2946753A
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crystals
materials
axis
rings
mixture
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Jonker Gerard Heinrich
Wijn Henricus Petrus Johannes
Braun Poul Bernard
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US Philips Corp
North American Philips Co Inc
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2683—Other ferrites containing alkaline earth metals or lead
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2608—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead
    • C04B35/2616—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead containing lithium
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2608—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead
    • C04B35/2625—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead containing magnesium
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2608—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead
    • C04B35/2633—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead containing barium, strontium or calcium

Definitions

  • Our invention relates to oxidic ferromar gireticv mate! rials, to methods of preparing-these materials and to bodies made from these materials. i,
  • theseniaterials show a-decrease of the initial, permeability in a certain frequency range the position of which in the frequency scaleis related to the low-frequency value of the initial permeability.
  • the initial permeability decreases ina frequencyrange the position of which in the frequency scale is higher in proportion as .the value of the initial permeability. at low-frequency is lower.
  • the cores :formed from these materials are not too satisfactory for use at high frequencies.
  • the principal object of our inventiom therefore, is to provide a new and novel class of oxidic, ferromagnetic materials theinitial permeability of which decreases in a much higher positioned frequency range than in the known materials-with an equal low frequency value of the initial permeability.
  • Another object of our invention is to provide oxidic quencies and which exhibit low losses.
  • Still anotheriobject of our mvention'is to-ipr'ovide oxidic ferromagnetic materials which may serveas mate ferromagnetic materials which have initial permeabilities Qof more and often materially more than 2 at frequencies rials for magnetic bodies e.g. cores at frequencies of -about.50'mc./ s and often considerably higher frequencies.
  • M represents one of the aforesaid divalent metals and the subscripts have the following value a less than 0.5 b less than 0.25 a less than 0.25
  • novel materials of our invention have a rhombqhedric crystal structure of which theunit cell in the hexagonal crystal system has a coaxis of about 43.5 A; and an axis of about 5.9 A.
  • a preformed reaction product of at least two of the ⁇ metallic oxides we. preferably use an iron-conta'ming novelmaterials having a -coniposition BaM FeJ O "wherein M is at least one divalent metal selected from 'the group consisting of Mn, Fe, Co, Ni, Cu,' Zn and-Mg.
  • M is at least one divalent metal selected from 'the group consisting of Mn, Fe, Co, Ni, Cu,' Zn and-Mg.
  • the aforesaid formula'Ba may-be replaced-partly by "similar ions, for example Sr, .Ca and Pb, since-the- Ba may be'replaced at amaximum forhalf by Sr or atf-a .”temperature of about 900 C.
  • the presinteijed .material,heing regroundand resintered several more if desired'before being-subjected to the higher tempera- :process we may. include, various flux agents, for example .silicates.such as pentonite or fluorides such as'calciurnmixtures.
  • reaction product which has been produced at lo'w tern- Jperaturo, preferably belovv '1l00 C., and which has a fcrystal structure corresponding with thatzof the mineral.
  • m agnet oplumbite for example Ba Sr Fe O where- .in Oxl- Q '5
  • the mixture of oxides and/or equivalent materials may be presintered, usually at a relatively low tures of the process.
  • IIlL'OldCF- to facilitate-the sintering operationof-cur fluoride in an amount of from 0.25 to 5 in the starting .Bodies of desired "grinding the sintered material of our invention or the -presinte'fedmaterial, molding the resultant powder .into
  • a binder such as water, a solution of nitrodo not decrease substantially up to very high frequencies;
  • a r divided te slp c invsmisn'is stat s "9 ism-i a cellulose or a solution of carboxymethylcellulose may be further embodiment of the invention the finely -sha pe may be' formed by sintering 'the starting mixtures directly in thedesired shape.
  • bodies ofdesired shape may be formed by rebody ofthe desired shape by pressing the relative material together with a binding agent which is capable of being hardened (for example a polyester resin) or an ethoxylin resin followed by hardening the molded body;
  • Figs. 1 to are graphs showing the relationship between the values of. the .real portion of initial permeability, 1., and the values of the loss factor, tan 6, to frequency for various embodiments of our invention.
  • u as used herein may .beexplained as 'follows: A sinusoidally alternating magnetic .field with small amplitude will produce a similarly varying inductance in a ferromagnetic body but due to ferromagnetic losses there will be a phase diflerence between the magnetic held and the inductance.
  • the real portion of permeability, ,u is in phase with the field-applied while the other lags in phase by 90 with respect to the applied field.
  • the loss factor tan 6 can then be defined as IT tan a 7
  • the BaCO was substantially pure, the Fe O contained 68.4% by weight of iron, the MgCO 26.2% by weight of magnesium, the C000 45.3% by Weight of cob-alt, the NiCO 46.1% by weight of nickel andthe ZnO 78.4% by weight of zinc.
  • Example II V n A n umber of rings of t'hezinc-containing material, described in Example 'I, were sintered for only half an 4
  • Example III A mixture of 26.0 gs. of BaCO 60.0 gs. of'Fe 0 and 9.5 gs. of NiO was ground with ethyl alcohol in a porcelain ball mill. The dried mixture was pres'intered for 15 hours at 1100 C.
  • Example IV Mixtures having the following compositions were produced:
  • Example'VI In the manner described in Example V, starting from a mixture of barium carbonate, calcium carbonate, zinc oxide and ferric oxide in a ratio in accordance with the formula Ba Ca Znles0 1, a material was produced tity of crystals with spinel crystal structure (probably hour at 1200 C. in oxygen and then cooled to room tem- 1 :iperature within about one hour. The properties of these rings are indicated in the table under N0. '5.
  • Zn Fe O was obtained as a second phase.
  • the properties of this compound are indicated :inthe table under a ratio in accordance with theitformula A rings are indicated 1 mi M .1
  • Example VIII v nrbmnaco, and re p, .in themole'cularratioof 5.6 by heating the mixture' for 15 hours at 900 0.
  • a material was produced which consisted primarilyof the'compound' 7 BaFe O 33 gs. o'fthis materialwas, mixed with 5.'2
  • Example IX 1 i The compounds am o BaFe Oi 32141.- of the material was mixed with: 6.05 gs. of
  • BaCO 4.9 gs. of ZnO and 2.33 gs. of C139 which. I corresponds to.'the desired compound BaZnFe Cr O 1 Q (.16)
  • the mixtures were ground for one hour with ethyl carbonate;leadearbonatc ind-'oxide afid ferric oxide 3 alcohol i a Porcelain ball mill and after dryingthey were. presintered for; two hours at 1000? C. in oxygen.
  • a ferromagnetic material consisting essentially of crystals of a composition having the formula:
  • M is at least one divalent metal selected from the group 1 consisting of Mn, Fe, Co, Ni, Cu, Zn, and Mg, and
  • a has a value less than 0.5 (b+c) has a value less than 0.25 (e-l-f) has a value less than 0.6
  • said crystals having a rhombohedric structure, of which the unitcell in thehexagonal. crystal systemcan belde ,scribed with a c-axis of about 43.5 A. and an .a-axis of -2. .Aierromagnetic body having an initial pemeability exceeding).
  • a has a value less than 0.5 (b+c) has a value less than 0.25 (e+f) has a value less than.0.6
  • said crystals having a rhombohedric structure, of which the 'unit cell in the hexagonal crystal can be described with a c-axis of about 43.5 A. and ana-axis of about 5.9 A. 1
  • a permanent magnet comprising a magnetized highly-coherent body consisting essentially of crystals of a composition having the formula:
  • M is at least one divalent metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, and Mg, and
  • a has a value less than 0.5
  • said crystals having a rhombohedric structure of which the unit cell in the hexagonal crystal system can be described with a c-axis of about 43.5 A. and an a-axis of about 5.9 A.
  • a method of producing a ferromagnetic material which comprises the steps, forming a finely-divided mixture of oxides in proportions forming upon heating crystals of a composition having the formula:
  • a method o produci g a: ferromagnetic material comprising the steps, forming a, finely-divided mixture 1 of divalent metal oxides inproportions forming upon subsequent heating crystals of a composition,. having the formula: Y
  • i i f M is a divalent metalselectedfrom the group of Mn, Fe, Co, Ni, Cu, ZnQand Mg, and z'zhas a'valueless-than0.5 f t (b+c) has a value less than 0:25
  • said crystals having a rhombohedric structure, of -which the unit cell can bedescribed with a c-axis of about 43 .5 A. and an a-axis of about 5.9 A.; heating said mixture to a temperature between about 900 to 1200 C. to react the same; finely-dividing the reaction product; and heating the finely-divided reacted product in an atmosphere containing at least as much oxygen as air to a temperature of about 1000" to 1300 C. for a time suflicient to form said crystals.
  • a method of producing a ferromagnetic body which comprises the steps forming a finely-divided mixture of oxides in proportions forming upon heating crystals of a composition having the formula:
  • i M is a divalent metal selected from the group consisting of Mn, Ife, Co, Ni, Cu, Zn, and Mg, and ahas a value less than 0.5 e 5 (b'+c) has a value less than 0.25 (e+ f) has a value less than 0.25,
  • said crystals having a rhombohedrio structure, of which the unit cell in the hexagonal system can be described consisting -Y'With a c-axis of about 43.5 A.,and an a-axis of about 5.9 A.'; compacting said mixture into a body of desired shape and dimensions; and heating said compacted body inan'a'tmosphere containing at least as much oxygen as with a c-axis of about 43.5 A. and an a-axis of about i 5.9 A.; and heating said mixture in an atmosphere containing at least as much oxygen as air at a temperature of about 1000" to 1300 C. for a time sutiicient tojform said crystals.
  • a method of producing a ferromagnetic material comprising the steps, forming a finely-divided mixture of divalent metal oxides and ferric oxide in proportions yielding upon heating crystals having a structure corre 'sponding to that of the mineral mangetoplumbite; heating said mixture at a temperature below 1100" C. and sufficiently high to form said crystals; mixing said crystals with additional oxides of divalent metals in amountssufficient to form upon heating crystals of a composition having the formula:
  • said latter crystals having a rhombohedric structure, of which the unit cell in the hexagonal system can be described with a c-axis of about 43.5 A. and an 'a-axis of about 5.9 A.; and heating the latter mixture in an atmosphere containing at least as much oxygen as air to a temair at a temperature of about 1000 to 1300 C. for a time sufiicient to form said crystals.
  • a method of producing a permanent magnet body which comprises the steps forming a finely-divided mixture of oxides in proportions forming upon heating crystals of a composition having the formula:
  • M is a, divalent metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, and Mg, and a has a value less than 0.5
  • said crystals having a rhombohedric structure, of which the unit cell in the hexagonal system can be described with a c-axis of about 43.5 A. and an a-axis of about 5.9 A.; compacting said mixture into a body of desired shapes and dimensions; heating said compacted body in 2,659,698 Berge Nov. 17, 1953 (Other references on following page) 9 UNITED STATES PATENTS Harvey Nov. 8, 1955 Crowley Feb. 28, 1956 Went Sept. 11, 1956 Gorter et a1. Sept. 11, 1956 Crowley Jan. 22, 1957 Medvediefi Mar. 25, 1958 FOREIGN PATENTS 1 10 France Apr. 13, 1955 OTHER REFERENCES Erchalk et al.: J. Amer. Chem. Soc., October 1946, pp. 2085-2093.
  • Patent should read as corrected below.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Compounds Of Iron (AREA)
  • Magnetic Ceramics (AREA)
  • Soft Magnetic Materials (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
US603136A 1955-08-10 1956-08-09 Ferromagnetic material Expired - Lifetime US2946753A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3043776A (en) * 1957-04-18 1962-07-10 Philips Corp Ferromagnetic oxidic material
US3093453A (en) * 1959-04-15 1963-06-11 Weizmann Inst Of Science Ferrite material containing fluorine
US3102099A (en) * 1957-06-22 1963-08-27 Philips Corp Method of manufacturing monocrystalline bodies
US3191132A (en) * 1961-12-04 1965-06-22 Mayer Ferdy Electric cable utilizing lossy material to absorb high frequency waves
US3319191A (en) * 1965-07-08 1967-05-09 Jr Samuel Dixon Microwave power limiter utilizing a planar ferrite sphere
US4243697A (en) * 1979-03-14 1981-01-06 The United States Of America As Represented By The Secretary Of The Air Force Self biased ferrite resonators
US20040119552A1 (en) * 2002-12-20 2004-06-24 Com Dev Ltd. Electromagnetic termination with a ferrite absorber

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123807A (en) * 1957-06-24 1964-03-03 Uiilljo

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2659698A (en) * 1949-01-03 1953-11-17 Aladdin Ind Inc Magnetic core and method for manufacturing same
DE927259C (de) * 1953-04-26 1955-05-02 Eisen & Stahlind Ag Oxydischer ferromagnetischer Werkstoff
FR1100865A (fr) * 1954-03-05 1955-09-26 Matériaux magnétiques à base d'oxydes pour la réalisation de bandes d'enregistrement magnétique
US2723239A (en) * 1952-09-29 1955-11-08 Rca Corp Ferrospinel compositions
US2736708A (en) * 1951-06-08 1956-02-28 Henry L Crowley & Company Inc Magnetic compositions
US2762777A (en) * 1950-09-19 1956-09-11 Hartford Nat Bank & Trust Co Permanent magnet and method of making the same
US2762778A (en) * 1951-12-21 1956-09-11 Hartford Nat Bank & Trust Co Method of making magneticallyanisotropic permanent magnets
US2778803A (en) * 1953-02-06 1957-01-22 Aerovox Corp Magnetically hard materials
US2828264A (en) * 1954-11-09 1958-03-25 Audax Manufacture process of permanent magnets from sintered mixtures of oxides

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2659698A (en) * 1949-01-03 1953-11-17 Aladdin Ind Inc Magnetic core and method for manufacturing same
US2762777A (en) * 1950-09-19 1956-09-11 Hartford Nat Bank & Trust Co Permanent magnet and method of making the same
US2736708A (en) * 1951-06-08 1956-02-28 Henry L Crowley & Company Inc Magnetic compositions
US2762778A (en) * 1951-12-21 1956-09-11 Hartford Nat Bank & Trust Co Method of making magneticallyanisotropic permanent magnets
US2723239A (en) * 1952-09-29 1955-11-08 Rca Corp Ferrospinel compositions
US2778803A (en) * 1953-02-06 1957-01-22 Aerovox Corp Magnetically hard materials
DE927259C (de) * 1953-04-26 1955-05-02 Eisen & Stahlind Ag Oxydischer ferromagnetischer Werkstoff
FR1100865A (fr) * 1954-03-05 1955-09-26 Matériaux magnétiques à base d'oxydes pour la réalisation de bandes d'enregistrement magnétique
US2828264A (en) * 1954-11-09 1958-03-25 Audax Manufacture process of permanent magnets from sintered mixtures of oxides

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3043776A (en) * 1957-04-18 1962-07-10 Philips Corp Ferromagnetic oxidic material
US3102099A (en) * 1957-06-22 1963-08-27 Philips Corp Method of manufacturing monocrystalline bodies
US3093453A (en) * 1959-04-15 1963-06-11 Weizmann Inst Of Science Ferrite material containing fluorine
US3191132A (en) * 1961-12-04 1965-06-22 Mayer Ferdy Electric cable utilizing lossy material to absorb high frequency waves
US3319191A (en) * 1965-07-08 1967-05-09 Jr Samuel Dixon Microwave power limiter utilizing a planar ferrite sphere
US4243697A (en) * 1979-03-14 1981-01-06 The United States Of America As Represented By The Secretary Of The Air Force Self biased ferrite resonators
US20040119552A1 (en) * 2002-12-20 2004-06-24 Com Dev Ltd. Electromagnetic termination with a ferrite absorber

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GB842005A (en) 1960-07-20
CH377268A (de) 1964-04-30
FR1169565A (fr) 1958-12-31
NL88300C (de) 1958-05-16
ES230262A1 (es) 1957-03-01

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