US2989476A - Ferrite with constricted magnetic hysteresis loop - Google Patents
Ferrite with constricted magnetic hysteresis loop Download PDFInfo
- Publication number
- US2989476A US2989476A US620315A US62031556A US2989476A US 2989476 A US2989476 A US 2989476A US 620315 A US620315 A US 620315A US 62031556 A US62031556 A US 62031556A US 2989476 A US2989476 A US 2989476A
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- United States
- Prior art keywords
- ferrite
- weight
- oxide
- hysteresis loop
- nickel
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- 229910000859 α-Fe Inorganic materials 0.000 title claims description 41
- 230000005291 magnetic effect Effects 0.000 title claims description 12
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 13
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 10
- 229910044991 metal oxide Inorganic materials 0.000 claims description 6
- 150000004706 metal oxides Chemical class 0.000 claims description 5
- GOECOOJIPSGIIV-UHFFFAOYSA-N copper iron nickel Chemical compound [Fe].[Ni].[Cu] GOECOOJIPSGIIV-UHFFFAOYSA-N 0.000 claims description 3
- PGUBMEQVDSYARE-UHFFFAOYSA-N [Mg].[Fe].[Ni] Chemical compound [Mg].[Fe].[Ni] PGUBMEQVDSYARE-UHFFFAOYSA-N 0.000 claims description 2
- 238000005245 sintering Methods 0.000 claims description 2
- UBEWDCMIDFGDOO-UHFFFAOYSA-N cobalt(2+);cobalt(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[Co+2].[Co+3].[Co+3] UBEWDCMIDFGDOO-UHFFFAOYSA-N 0.000 claims 2
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 15
- 238000004804 winding Methods 0.000 description 12
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 10
- 239000000395 magnesium oxide Substances 0.000 description 8
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 239000010949 copper Substances 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- YOCUPQPZWBBYIX-UHFFFAOYSA-N copper nickel Chemical compound [Ni].[Cu] YOCUPQPZWBBYIX-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- PCTMTFRHKVHKIS-BMFZQQSSSA-N (1s,3r,4e,6e,8e,10e,12e,14e,16e,18s,19r,20r,21s,25r,27r,30r,31r,33s,35r,37s,38r)-3-[(2r,3s,4s,5s,6r)-4-amino-3,5-dihydroxy-6-methyloxan-2-yl]oxy-19,25,27,30,31,33,35,37-octahydroxy-18,20,21-trimethyl-23-oxo-22,39-dioxabicyclo[33.3.1]nonatriaconta-4,6,8,10 Chemical compound C1C=C2C[C@@H](OS(O)(=O)=O)CC[C@]2(C)[C@@H]2[C@@H]1[C@@H]1CC[C@H]([C@H](C)CCCC(C)C)[C@@]1(C)CC2.O[C@H]1[C@@H](N)[C@H](O)[C@@H](C)O[C@H]1O[C@H]1/C=C/C=C/C=C/C=C/C=C/C=C/C=C/[C@H](C)[C@@H](O)[C@@H](C)[C@H](C)OC(=O)C[C@H](O)C[C@H](O)CC[C@@H](O)[C@H](O)C[C@H](O)C[C@](O)(C[C@H](O)[C@H]2C(O)=O)O[C@H]2C1 PCTMTFRHKVHKIS-BMFZQQSSSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- 229910018054 Ni-Cu Inorganic materials 0.000 description 2
- 229910018481 Ni—Cu Inorganic materials 0.000 description 2
- 229910018505 Ni—Mg Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000005307 ferromagnetism Effects 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- ATTFYOXEMHAYAX-UHFFFAOYSA-N magnesium nickel Chemical compound [Mg].[Ni] ATTFYOXEMHAYAX-UHFFFAOYSA-N 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910000480 nickel oxide Inorganic materials 0.000 description 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 2
- 229910052573 porcelain Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000012552 review Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910002642 NiO-MgO Inorganic materials 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 235000013495 cobalt Nutrition 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000001238 wet grinding Methods 0.000 description 1
Images
Classifications
-
- 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
- C04B35/265—Compositions containing one or more ferrites of the group comprising manganese or zinc and one or more ferrites of the group comprising nickel, copper or cobalt
Definitions
- Ferromagnetic metals with constricted hysteresis loops have, as is well known, at small field strength within the constriction area, constant permeability, i.e., permeability independent of the field strength equal to the initial permeability, very low hysteresis losses and, in general, small residual losses.
- thermomagnetic treatment in this connection, is meant the passing through a thermic cycle during the simultaneous presence of a magnetic longitudinal or transverse field.
- longitudinal or transverse field is, in this connection, to be understood as relative to the later measuring field; a longitudinal or transverse field, respectively, means that such field, during the thermomagnetic treatment, is parallel, respectively vertical, to the later measuring field.
- T hm this type of treatment, these ferromagnetic materials display a substantial alteration of the form of the hysteresis loop, and hence a change ofthe magnetic properties.
- the invention teaches the production of such fern'tes of thenickel-copper or nickel-magnesium ferrite-systen. which can be subjected to thermomagnetic treatment of the above type, and are distinguished from hitherto familiar ferrites by the fact that, under the same manufacturing conditions, they have constricted hysteresis loops.
- ferrites with this characteristic in the nickel-copper or nickel-magnesium-ferritesystem must have a composition of at least 50 mol percent Fe O and a small addition of cobalt oxide.
- the addition of cobalt oxide is suitably determined between. 0.1 and 5% by weight, calculated on the total basic batch of the nickel-copper or nickel-magnesium-ferrite, expressed in metallic oxides. The invention has shown that it is par-.
- the above ferrites may be prepared in the usual way, either by joint or partial precipitation, from correspondingmetal salt solutions, or, as is customary in ceramic arts, they may be prepared for further processing by wet milling and mixing of the respective metal oxides.
- the powdered mixtures thus obtained may after drying be given the desired form either immediately by dry pressing, extruding, or similar methods, or it may be desirable, before ceramic forming, to proceed with a calcining firing of the entire composition or only a part thereof, prefer-ably between 750 C. and 1100 C. for the Ni-Cu ferrite or 750 C. and 1250" C. for the Ni-Mg ferrite.
- the resultant parts are sintered, depending on the composition, in a suitable way between 1180 C. and 1350 C. for the Ni-Cu ferrite or 1250 C. and 1400 C. for the Ni-Mg ferrite system.
- the cooling takes place slowly, particularly in the temperature range between 700 C. and room temperature.
- the cooling speed is dependent upon the volume of the fired body. As a criterion, it may be stated that for a ring of about 46 mm. outside diameter, 34 mm. inside diameter, and 10 mm. height, the cooling time from 700 C.
- (a) for the NiO-CuO-Fe O system In a steel ball mill are ground together 387.5 g. Fe O g. NiO, 37.5 g. C010, 3.25 g. C00. After 6 hours of grinding, the slip is poured through a 4900 mesh screen (4900 meshes per square cm.) into a porcelain dish, and dried. The powder thus obtained, is pressed, according to ceramic pressing techniques, into rings having dimensions of 59 mm. outside diameter, 35.8 mm. inside diameter, and 12 mm. height, the amount of pressure applied being about 0.5 to -l t./cm.'-. The resulting ferrite pieces, are sintered in a kiln at 1320 C.
- the rings are cooled to room temperature in the kiln during a period of approximately 24 hours.
- the ferrite rings thus obtained are provided with 0.4 mm. copper enameled wire with windings as primary winding, and, as secondary winding, further 200 windings with 0.2 mm. copper enameled wire are applied.
- FIG. 1a In the oscillographic photograph of this ferrite, produced in accordance with the invention, which is shown in FIG. 1a, one can distinctly recognize the loop constriction of the hysteresis loop.
- the rings are cooled to room temperature in the kiln for a period of approximately 24 hours.
- the ferrite rings thus obtained are provided with 0.4 mm. copper enameled wire with 100 windings as primary winding, and, as secondary winding, further 200 windings with 0.2 mm. copper enameled wire are applied.
- the oscillogi'aphic photograph of this ferrite, produced in accordance with the invention, which is shown in FIG. 2a one can distinctly recognize the loop constriction of the hysteresis loop.
- the ferrite toroid of the example with 100 windings as a primary winding is placed in a kiln. While heating to 600 C., and slow cooling for 12 hours to room tem perature, a longitudinal magnetic field is maintained by means of the ring winding by 1 a. direct current, corresponding to a magnetic field strength of about 15 a.- windings/cm. If the hysteresis loop of the ferrite after this thermomagnetic treatment is recorded in the same manner as described above, the result is analogous to that of metals when they are subjected to heat treatment in the longitudinal magnetic field; a complete change of the form of the hysteresis loop, as may be seen in FIGS. 1b and 2b, takes place. In analogous manner, heat treatment in the transverse magnetic field may be carried out with corresponding effect; (see the above cited book by Bozorth).
- ferrites with distinctly rectangular hysteresis loop may be produced which are of importance to the entire fields of electronics and for magnetic amplification, for telephone and high-frequency fields;
- ferrities of high quality and a permeability independent of field strength may be produced, which are particularly suitable for the field of telecommunication.
- a cobalt-modified ferrite with a constricted magnetic hysteresis loop said ferrite being of the class consisting of nickel-copper-iron and nickel-magnesium-iron systems containing 0.1 to by weight of cobalt oxide, the iron oxide content of said composition being at least 50 mol percent expressed in metal oxides, said ferrite exclusive of the cobalt oxide content containing about 72.5 to 90% by weight of ferric oxide, about to 27.5% by weight of MO and the remainder consisting essentially of a metal oxide selected from the group consisting of up to by weight of CH0 and up to 22.5% by weight of MgO, said ferrite being formed by sintering at about 1180 C. to about 1400" C. and cooling the sintered ferrite from 700 C. down to room temperature over a period of at least twelve hours.
- A 27.5% NiO, 0% CuO, 72.5% Fe O by weight
- B 2.5% NiO, 25% CuO, 72.5% Fe O by weight
- C 2.5% NiO, 7.5% CuO, 90% Fe O by weight
- D l0% NiO, 0% CuO, 90% R2 0 by weight.
- A 27.5 NiO, 0% MgO, 72.5% Fe O by weight
- B 2.5% NiO, 22.5% MgO, F6203, by weight
- C 2.5% NiO, 7.5% MgO, Fe o by weight
- a process for preparing cobalt-modified ferrites selected from the class consisting of nickel-copper-iron ferrites containing at least 50 mol percent of iron oxide plus 0.1 to 5% by weight of cobalt oxide and nickelmagnesium-iron ferrites containing at least 50 mol per cent of iron oxide plus 0.1 to 5% by weight of cobalt oxide comprising intimately mixing ferric oxide, nickel oxide, cobalt oxide and an oxide selected from the group consisting of copper oxide and magnesium oxide in the proportions required to provide at least 50 mol percent of ferric oxide and 0.1 to 5% by weight of cobalt oxide the remainder being said other specified oxides, molding said powder mixture to shape, firing the molded article at about 1180 C. to about 1400 C. and thereafter slowly cooling the fired body from 700 C. down to room temperature over a period of at least about 12 hours to provide a ferrite body having a constricted hysteresis loop.
- Bozorth Physical Reviews, Sept. 15, 1955, p. 1792.
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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)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE849464X | 1955-10-29 | ||
| DEST10528A DE1057256B (de) | 1955-10-29 | 1955-11-10 | Verfahren zur Herstellung von ferromagnetischen Ferritkoerpern mit eingeschnuerter Hystereseschleife |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2989476A true US2989476A (en) | 1961-06-20 |
Family
ID=25950195
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US620315A Expired - Lifetime US2989476A (en) | 1955-10-29 | 1956-11-05 | Ferrite with constricted magnetic hysteresis loop |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US2989476A (de) |
| DE (1) | DE1057256B (de) |
| FR (1) | FR1159944A (de) |
| GB (1) | GB849464A (de) |
| NL (1) | NL110779C (de) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3100194A (en) * | 1958-01-15 | 1963-08-06 | Philips Corp | Ferromagnetic material and method of making the same |
| US6251299B1 (en) * | 1998-12-28 | 2001-06-26 | Tdk Corporation | Magnetic material, inductance element using the same and manufacturing method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL252610A (de) * | 1959-06-17 | |||
| NL272060A (de) * | 1960-12-06 |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE510462A (de) * | 1951-04-09 | |||
| US1976230A (en) * | 1930-12-25 | 1934-10-09 | Mitsubishi Electric Corp | Permanent magnet and method of manufacturing same |
| US1997183A (en) * | 1932-05-21 | 1935-04-09 | Clarence T Rottler | Sharpening tool |
| US2549089A (en) * | 1948-12-15 | 1951-04-17 | Rca Corp | Mixed ferrite compositions, including lithium ferrite |
| US2568881A (en) * | 1948-12-28 | 1951-09-25 | Steatite Res Corp | Ceramic parts for electrical devices having magnetic properties and method of making |
| US2656319A (en) * | 1949-01-03 | 1953-10-20 | Aladdin Ind Inc | Magnetic core composition and method of producing the same |
| 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 |
| GB748070A (en) * | 1953-12-21 | 1956-04-18 | Philips Electrical Ind Ltd | Improvements in or relating to methods of manufacturing ferromagnetic cores having substantially rectangular hysteresis loops |
| FR1125577A (fr) * | 1955-05-03 | 1956-11-02 | Lignes Telegraph Telephon | Matériaux ferromagnétiques à cycle d'hystérésis rectangulaire |
| US2778803A (en) * | 1953-02-06 | 1957-01-22 | Aerovox Corp | Magnetically hard materials |
| US2860105A (en) * | 1953-12-21 | 1958-11-11 | Philips Corp | Method of manufacturing ferromagnetic cores |
| US2886530A (en) * | 1955-07-19 | 1959-05-12 | Greger Herbert Hans | Process of manufacturing ceramic ferrites |
Family Cites Families (1)
| 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 |
-
1955
- 1955-11-10 DE DEST10528A patent/DE1057256B/de active Pending
-
1956
- 1956-10-26 NL NL211693A patent/NL110779C/xx active
- 1956-10-27 FR FR1159944D patent/FR1159944A/fr not_active Expired
- 1956-10-29 GB GB32921/56A patent/GB849464A/en not_active Expired
- 1956-11-05 US US620315A patent/US2989476A/en not_active Expired - Lifetime
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1976230A (en) * | 1930-12-25 | 1934-10-09 | Mitsubishi Electric Corp | Permanent magnet and method of manufacturing same |
| US1997183A (en) * | 1932-05-21 | 1935-04-09 | Clarence T Rottler | Sharpening tool |
| US2549089A (en) * | 1948-12-15 | 1951-04-17 | Rca Corp | Mixed ferrite compositions, including lithium ferrite |
| US2568881A (en) * | 1948-12-28 | 1951-09-25 | Steatite Res Corp | Ceramic parts for electrical devices having magnetic properties and method of making |
| US2656319A (en) * | 1949-01-03 | 1953-10-20 | Aladdin Ind Inc | Magnetic core composition and method of producing the same |
| BE510462A (de) * | 1951-04-09 | |||
| US2736708A (en) * | 1951-06-08 | 1956-02-28 | Henry L Crowley & Company Inc | Magnetic compositions |
| 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 |
| GB748070A (en) * | 1953-12-21 | 1956-04-18 | Philips Electrical Ind Ltd | Improvements in or relating to methods of manufacturing ferromagnetic cores having substantially rectangular hysteresis loops |
| US2860105A (en) * | 1953-12-21 | 1958-11-11 | Philips Corp | Method of manufacturing ferromagnetic cores |
| FR1100865A (fr) * | 1954-03-05 | 1955-09-26 | Matériaux magnétiques à base d'oxydes pour la réalisation de bandes d'enregistrement magnétique | |
| FR1125577A (fr) * | 1955-05-03 | 1956-11-02 | Lignes Telegraph Telephon | Matériaux ferromagnétiques à cycle d'hystérésis rectangulaire |
| US2886530A (en) * | 1955-07-19 | 1959-05-12 | Greger Herbert Hans | Process of manufacturing ceramic ferrites |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3100194A (en) * | 1958-01-15 | 1963-08-06 | Philips Corp | Ferromagnetic material and method of making the same |
| US6251299B1 (en) * | 1998-12-28 | 2001-06-26 | Tdk Corporation | Magnetic material, inductance element using the same and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1159944A (fr) | 1958-07-03 |
| GB849464A (en) | 1960-09-28 |
| NL110779C (de) | 1965-03-15 |
| DE1057256B (de) | 1959-05-14 |
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