GB696250A - Improvements in and relating to ferromagnetic materials - Google Patents

Improvements in and relating to ferromagnetic materials

Info

Publication number
GB696250A
GB696250A GB13535/51A GB1353551A GB696250A GB 696250 A GB696250 A GB 696250A GB 13535/51 A GB13535/51 A GB 13535/51A GB 1353551 A GB1353551 A GB 1353551A GB 696250 A GB696250 A GB 696250A
Authority
GB
United Kingdom
Prior art keywords
crucible
nitrogen
melting point
slowly
ferrite
Prior art date
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
Application number
GB13535/51A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philips Electrical Industries Ltd
Original Assignee
Philips Electrical Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Philips Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB696250A publication Critical patent/GB696250A/en
Expired legal-status Critical Current

Links

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

Abstract

<PICT:0696250/III/1> A body of single or mixed ferrite material having an initial permeability of at least 20, a loss factor tans of not more than 0.06 at frequencies up to 10KC as measured on a solid ring of the material, and a pore volume of less than 5 per cent, is obtained by solidification from a melt. In making manganese ferrite a chamotte crucible 1 is filled with aluminium oxide powder 2 heated to just below its melting point into which is pressed an aluminium oxide crucible 3. Inside this discs 5 of Fe3O4 alternate with layers 6 of Mn3O4. The crucible has a thermocouple 4 attached and is covered with an iridium plate 7. Nitrogen is led at 11, 12 through the surrounding glass dome 8 and the contents of the crucible heated slowly by h.f. currents in the coil 10 until just below their melting point. The nitrogen is gradually replaced by oxygen, the temperature is then raised until the oxides melt, maintained for five minutes, slowly reduced until the oxides resolidify and then rapidly reduced to 1300 DEG C. The oxygen is replaced by nitrogen and the cooling completed slowly. Sufficient heat is produced by induction because both the Fe3O4 used as a starting material and the ferrite at high temperatures have relatively high conductivity. As an alternative the crucible may be of high melting point alloy, e.g. platinum with iridium and/or rhodium. Also the molten material may be cast in a mould. Specification 696,216, [Group XXXV], is referred to.
GB13535/51A 1950-12-08 1951-06-07 Improvements in and relating to ferromagnetic materials Expired GB696250A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL696250X 1950-12-08

Publications (1)

Publication Number Publication Date
GB696250A true GB696250A (en) 1953-08-26

Family

ID=19808882

Family Applications (1)

Application Number Title Priority Date Filing Date
GB13535/51A Expired GB696250A (en) 1950-12-08 1951-06-07 Improvements in and relating to ferromagnetic materials

Country Status (3)

Country Link
BE (1) BE504598A (en)
DE (1) DE968299C (en)
GB (1) GB696250A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2842500A (en) * 1954-10-18 1958-07-08 Ibm Method of making ferrite structures
US3028337A (en) * 1957-10-15 1962-04-03 Ibm Method of preparing ferrite cores

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2993011A (en) * 1956-04-26 1961-07-18 Westinghouse Electric Corp Process for producing lithium substituted transition metal oxides and members prepared therefrom
US3546122A (en) * 1966-08-26 1970-12-08 Nippon Columbia Method of making oxide magnetic material
DE3041960C2 (en) * 1979-11-08 1983-07-21 Tokyo Shibaura Denki K.K., Kawasaki, Kanagawa A method of manufacturing magnetic powder for high density magnetic recording

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE226347C (en) *
DE227787C (en) *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2842500A (en) * 1954-10-18 1958-07-08 Ibm Method of making ferrite structures
US3028337A (en) * 1957-10-15 1962-04-03 Ibm Method of preparing ferrite cores

Also Published As

Publication number Publication date
DE968299C (en) 1958-01-30
BE504598A (en)

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