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US2946752A - Ferromagnetic material - Google Patents

Ferromagnetic material Download PDF

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Publication number
US2946752A
US2946752A US603135A US60313556A US2946752A US 2946752 A US2946752 A US 2946752A US 603135 A US603135 A US 603135A US 60313556 A US60313556 A US 60313556A US 2946752 A US2946752 A US 2946752A
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United States
Prior art keywords
crystals
mixture
rings
hours
materials
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Expired - Lifetime
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US603135A
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English (en)
Inventor
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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US Philips Corp
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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
    • C04B35/2608—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

  • the novel materials of our invention have a crystal structure of which the unit cell'in the hexagonal crystal system has a -axis of about 52.3 A and an a-axis of about5.9 A. w a a
  • We prepare'the novel materials of'our invention by heating at a temperature of more than 1200f C. a finely bility in a certain frequency range the position of which in the frequency scale is related to the low-frequency value of the initial permeability.
  • the initial permeability decreases in a frequency range 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 ourinvention is to provide a new and novel class of oxidic ferromagnetic materials the initial permeability of which decreases in I;
  • Another object of our'inven'tion is to provide oxidic ferromagnetic materials which have initial permeabilities of more and often materially more than 2 at frequencies of about 50 mc./s. and often considerably higher 'frequencies and which exhibit lowvlo sses, Q r
  • Still another object ,of our invention is to provide oxidic ferromagnetic materials which may serve as materials for magnetic, bodies eg. cgres at'frequencies of about 5'0 mc./s. and often considerably higher frequencies. r g
  • metallic oxides in a ratio approximately corresponding to that of the metals in the materials or our'invention.
  • a metallic oxide we may use a material which forms an oxide when heated.
  • these oxide-forming materials we may use carbonates, oxalates and acetates of the metals.
  • metallic oxides we may use one or more preformed reaction products of at least two of the metallic oxides.
  • the novel materials of our invention by heating. to a temperature of more than .1200 C. in an. atmosphere containing at least as much; oxygen .as air, a finely divided mixture of metallic oxides and/ or oxide-forming. materials and/or reaction products of metallic oxides; in a ratio approximately corresponding to that of the metals in the materials of our invention.
  • an iron-containing reaction product which has been produced at low temperature, preferably below 1100 C., and which has a crystal structure corresponding with that of the mineral magnetoplumbite, for exampleBa Sr Fe O wheresilicates such as pentonite or fluorides such as calcium fluoride in an amount of from 0.25% to 5% in the mix- Bodies of desired shape maybe formed by sintering the starting mixtures directly in the desired shape.
  • bodies of desired shape. may be formed by regrmding the sintered material of our invention, or the presintered material, molding the resultant powder into ions, i.e. for not more than one third part.
  • the aforesaid formula may thus be restated as follows:
  • M is-at least one metal selected from the group consisting of strontium, calcium, andlead, and the subs p 4 avalu l ss than T
  • M is-at least one metal selected from the group consisting of strontium, calcium, andlead
  • the subs p 4 avalu l ss than T Thesem s alahav initial permeabilities which do not decrease substantial-g ly up to very high frequencies; They haveinitial per meabilities of more and often materially more than. 2. at frequencies of about 50 mc./s. and often considerably Since they are basically oxidic in nature they are characterized by high ohmic resisltancem'; so that eddy current losses are negligibly'small. 'In 'ad f dition to having greatly improvedinitialpermeabilities higher frequencies.
  • a binder such as water, a solution of'nitrocellulose or a solution of carboxymethylcellulose may be addedto the powdered mixtures before molding if necessary. 7
  • the finely divided material of our invention is molded to forma body of the desired shape by pressing the relative material together with a binding agent which is capable of being hardened (for example'a polyester resinor an 'ethoxylin resin), followed'by hardening the molded body.
  • a binding agent which is capable of being hardened (for example'a polyester resinor an 'ethoxylin resin), followed'by hardening the molded body.
  • Fig. 2 is a graph showing the relationship between the yaliiefslof the real portion of initial permeability, IL, and
  • the term p asused herein may be explained as 5, at a pressure of 1000 kgs./cm. having an outer diameter of about 35 mms, an inner diameter of about 25 rnms. and a height of about 4 mms. These rings were sintered for two hours at 1260 C. in oxygen.
  • the properties are ance in a ferromagnetic body but due to ferromagnetic indicated in the table under N0. 4. losses there will be a phase difierence between the mag- Example V netic field and the inductance.
  • the permeability of the ferromagnetic body, ,u may be represented by a com- 10 i PQ 12 19 was p l Produced y Plex magnitude m"
  • the loss factor tan 6 can then be defined as mols 12 19 1 1110133003 and 2 H1015 Cocoa, Winch 15 corresponds'to the desired formula Ba Co Fe O
  • the tan mixture was ground with alcohol in a vibration mill for n 4 hours. Rings were molded from this product at a Example 1 pressure of 1000 kgs/cmP; these rings were fired for one hour at 1270 C. in oxygen.
  • Example VII Example Ill 40 a e A mixture of cobalt carbonate barium carbonate and A mixture of 23.0 gs. of BaCO 72.5 gs. of Fe O and 795 gs.
  • Fig. 1 shows the relationship between the real portion of the initial permeabi.lty, ,u', and tan 6 to frequency for the product of Example II.
  • the values of ,u, and tan 6 are plotted along the ordinates and the values of the frequencies are plotted along the abscissa.
  • a ferromagnetic material consisting essentially of crystals of a composition having the formula v I-a a 2 24 41 in which M is a metal selected from the group consisting of strontium, calcium, and lead, and a has a value less than 1, said compound containingas the equivalent a total of 17.6 mol. percent of barium, strontium, calcium and lead oxides, 11.8 mol. percent of C00 and 70.6 mol.
  • unit cell of which in the hexagonal cry'stal system has a c-axis. of about 52.3 Aand an 'a-axis of about 5.9 A.
  • M is a metal selected from the group consisting of strontium, calcium, and lead and a has a value less than 1, said crystals having a structure, the unit cell of which in the hexagonal system has a c-axis of 52.3 A and an a-axis of about 5.9 A.
  • a method of producing a ferromagnetic material comprising the steps, forming a finely-divided mixture of oxides in proportions forming upon sintering crystals of a composition having the formula:
  • M is a metal selected from the group consisting of calcium, strontium, and lead and a has a value less than 1, said crystals having a structure, the unit cell of which in the hexagonal crystal system has a c-axis of 52.3 A and an a-axis of about 5.9 A; and heating said mixture to a temperature of at least 1200 C. in an atmosphere containing at least as much oxygen as air for a time sufficient to form the crystals.
  • a method of producing a-ferromagnetic material comprising the steps, forming a finely-divided mixture of oxides of divalent metals and ferric oxide in propor tions forming upon heatingcrystals having a structure so. sisting essentially of a highly coherent mass of crystals correspondingtothe mineral; magnetoplumbite; heat-j ing said mixture. to a temperaturebelow ,1100 C; but
  • a method of producing a ferromagnetic material comprising the steps, forming a finely-divided mixture of oxides in proportions forming upon subsequent heating crystals of a composition having the formula:
  • M is a metal selected from the group consist -'-ing of strontium, calcium, and lead, and a has a value lessthan 1, said crystals having a structure, the unit 'cell of which in vthe hexagonal crystal'system has a c -axis I of about 52.3 A and an a-axis of about 5.9 A; heating 1 said mixture to a temperature of about 800 to 1100 C. to substantially react the oxides into forming said composition; finely-dividing said reaction product; and heat- I ing said finely-divided reaction product at a temperature of at least about 1200 C. in an atmosphere containing at least as much oxygen as air for a time sufficient to form said crystals.
  • a method of making a ferromagnetic body having an initial permeability exceeding at least 2 at a frequency of at least 50 mc./sec. comprising the steps, forming a finely-divided mixture of oxides in proportions forming upon heating crystals of a composition having the,

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Magnetic Ceramics (AREA)
  • Compounds Of Iron (AREA)
  • Hard Magnetic Materials (AREA)
US603135A 1955-08-10 1956-08-09 Ferromagnetic material Expired - Lifetime US2946752A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL199609 1955-08-10

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US2946752A true US2946752A (en) 1960-07-26

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US (1) US2946752A (el)
BE (1) BE550224A (el)
CH (1) CH376414A (el)
DE (1) DE1148478B (el)
FR (1) FR1163019A (el)
GB (1) GB839860A (el)
LU (1) LU34573A1 (el)
NL (1) NL88282C (el)

Cited By (8)

* 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
US3053618A (en) * 1960-11-23 1962-09-11 Owens Illinois Glass Co Method for making titanium, zirconium and tin tellurites
US3053619A (en) * 1960-11-30 1962-09-11 Owens Illinois Glass Co Method of producing cerium tellurite
US3102099A (en) * 1957-06-22 1963-08-27 Philips Corp Method of manufacturing monocrystalline bodies
US3177145A (en) * 1963-02-04 1965-04-06 Ibm Manganese copper ferrite composition containing titanium and germanium and method ofpreparation
US4280846A (en) * 1978-08-01 1981-07-28 Thomson-Csf Method of fabrication of dielectric material having volume-distributed insulating barriers for use at high voltages and a ceramic body fabricated by said method
US5954992A (en) * 1996-07-26 1999-09-21 Tdk Corporation Hexagonal Z type magnetic oxide sintered material, method for making and impedance device
US6033593A (en) * 1997-06-17 2000-03-07 Tdk Corporation BALUN transformer core material, BALUN transformer core and BALUN transformer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112851326A (zh) * 2021-01-29 2021-05-28 兰州大学 一种Co2Z型铁氧体材料及其制备方法

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
US2762778A (en) * 1951-12-21 1956-09-11 Hartford Nat Bank & Trust Co Method of making magneticallyanisotropic permanent magnets
US2762777A (en) * 1950-09-19 1956-09-11 Hartford Nat Bank & Trust Co Permanent magnet and method of making the same
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 (8)

* 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
US3053618A (en) * 1960-11-23 1962-09-11 Owens Illinois Glass Co Method for making titanium, zirconium and tin tellurites
US3053619A (en) * 1960-11-30 1962-09-11 Owens Illinois Glass Co Method of producing cerium tellurite
US3177145A (en) * 1963-02-04 1965-04-06 Ibm Manganese copper ferrite composition containing titanium and germanium and method ofpreparation
US4280846A (en) * 1978-08-01 1981-07-28 Thomson-Csf Method of fabrication of dielectric material having volume-distributed insulating barriers for use at high voltages and a ceramic body fabricated by said method
US5954992A (en) * 1996-07-26 1999-09-21 Tdk Corporation Hexagonal Z type magnetic oxide sintered material, method for making and impedance device
US6033593A (en) * 1997-06-17 2000-03-07 Tdk Corporation BALUN transformer core material, BALUN transformer core and BALUN transformer

Also Published As

Publication number Publication date
NL88282C (el) 1958-05-16
DE1148478B (de) 1963-05-09
CH376414A (de) 1964-03-31
BE550224A (el) 1957-02-09
FR1163019A (fr) 1958-09-22
LU34573A1 (el) 1956-10-09
GB839860A (en) 1960-06-29

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