GB1268458A - Improvements in and relating to the preparation of cobalt doped gamma ferric oxide - Google Patents
Improvements in and relating to the preparation of cobalt doped gamma ferric oxideInfo
- Publication number
- GB1268458A GB1268458A GB1443470A GB1443470A GB1268458A GB 1268458 A GB1268458 A GB 1268458A GB 1443470 A GB1443470 A GB 1443470A GB 1443470 A GB1443470 A GB 1443470A GB 1268458 A GB1268458 A GB 1268458A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cobalt
- mixture
- heating
- alpha
- compound
- 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
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70652—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3
- G11B5/70668—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant
- G11B5/70673—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant containing Co
Landscapes
- Hard Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Paints Or Removers (AREA)
Abstract
1,268,458. Magnetic materials. AMPEX CORP. 25 March, 1970 [7 May, 1969], No. 14434/70. Heading HlH. [Also in Division Cl] Acicular cobalt-doped gamma Fe 2 O 3 is prepared by selecting an iron compound from alpha FeOOH and alpha Fe 2 O 3 , the compound consisting of particles having an average length of between 0À1 and 2À0 microns and a length to width ratio of at least 1À5 to 1, forming an aqueous mixture of an iron compound with either cobalt nitrate, cobalt acetate or cobalt formate the proportion of cobalt in the mixture being from 0À5 to 25 atomic % of the iron, drying the mixture, heating the dried mixture at a temperature between 150‹ and 600‹ C. to produce cobalt doped alpha Fe 2 O 3 , heating this in a hydrogen atmosphere at a temperature of not more than 600‹ C. to produce cobalt doped Fe 3 O 4 and heating this in an atmosphere of free oxygen at a temperature between 100‹ and 600‹ C. to produce the desired product. If the iron compound is alpha FeOOH it may be dehydrated by heating before or after being mixed with the cobalt compound. Sodium hydroxide may be added to the aqueous mixture, before the mixture is dried, to precipitate the cobalt as the hydroxide. The product of the invention has specified magnetic properties, e.g. a coercivity ranging from 265-765 oersteds. Saturation and remanent magnetization values are given in the examples. As illustrated by Example 5 the product of the invention may be made into tapes by mixing with carbon black, P.V.C. resin, lecithin and solvents, and after mixing adding more P.V.C. resin, polyurethane resin and further solvents, continuing mixing and then coating the resultant slurry on polyester film. Test results for such tapes are given in the example. In other examples other resins, e.g. butylated melamine formaldehyde and vinylidene chloride acrylonitrile are specified together with dispersing and other agents.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US82270969A | 1969-05-07 | 1969-05-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1268458A true GB1268458A (en) | 1972-03-29 |
Family
ID=25236749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1443470A Expired GB1268458A (en) | 1969-05-07 | 1970-03-25 | Improvements in and relating to the preparation of cobalt doped gamma ferric oxide |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE750031A (en) |
| DE (1) | DE2022013C2 (en) |
| FR (1) | FR2047369A5 (en) |
| GB (1) | GB1268458A (en) |
| NL (1) | NL7004295A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4287233A (en) | 1979-02-13 | 1981-09-01 | Basf Aktiengesellschaft | Manufacture of acicular cobalt-containing magnetic iron oxide |
| US4296149A (en) | 1979-02-13 | 1981-10-20 | Basf Aktiengesellschaft | Manufacture of acicular cobalt-containing magnetic iron oxide |
| US4306921A (en) | 1978-03-16 | 1981-12-22 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| US4384892A (en) | 1978-03-16 | 1983-05-24 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| DE3245635A1 (en) * | 1981-12-09 | 1983-06-16 | Japan Metals & Chemicals Co., Ltd., Tokyo | Process for producing a ferromagnetic oxide |
| CN113106484A (en) * | 2021-04-07 | 2021-07-13 | 西南大学 | Hydrothermal preparation method of novel photo-anode based on alpha-type iron oxide vermicular nano-structure array, product and application thereof |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2243231C2 (en) * | 1972-09-01 | 1982-01-28 | Basf Ag, 6700 Ludwigshafen | Process for the preparation of cobalt-doped γ-iron (III) oxide |
| DE2639250C2 (en) * | 1976-09-01 | 1985-12-12 | Basf Ag, 6700 Ludwigshafen | Process for the production of acicular, cobalt-doped magnetic iron oxide |
| DE2903593C3 (en) * | 1979-01-31 | 1982-05-06 | Bayer Ag, 5090 Leverkusen | Cobalt-doped ferrimagnetic iron oxides and processes for their production |
| DE2935444A1 (en) * | 1979-09-01 | 1981-03-19 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING NEEDLE SHAPED FERRIMAGNETIC IRON OXIDE |
| JPS60137002A (en) * | 1983-12-26 | 1985-07-20 | Toda Kogyo Corp | Manufacture of tabular ba ferrite fine particle powder for magnetic recording |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB721630A (en) * | 1951-08-29 | 1955-01-12 | Anorgana Gmbh | Method for the production of ª†-fe o of improved magnetic properties |
| GB719283A (en) * | 1951-09-20 | 1954-12-01 | Philips Electrical Ind Ltd | Improvements in or relating to a method of producing finely divided magnetic iron oxide |
| DE936392C (en) * | 1953-12-03 | 1955-12-15 | Basf Ag | Process for the production of magnetic iron oxides |
| US3117933A (en) * | 1959-06-12 | 1964-01-14 | Bayer Ag | Process for the production of needleshaped, cobalt-containing gamma-ferric oxide crystalline particles |
| US3278440A (en) * | 1960-11-22 | 1966-10-11 | William J Schuele | Shaped fine particle ferrites and method for their preparation |
-
1970
- 1970-03-25 GB GB1443470A patent/GB1268458A/en not_active Expired
- 1970-03-25 NL NL7004295A patent/NL7004295A/xx unknown
- 1970-05-05 DE DE19702022013 patent/DE2022013C2/en not_active Expired
- 1970-05-06 BE BE750031D patent/BE750031A/en not_active IP Right Cessation
- 1970-05-06 FR FR7016520A patent/FR2047369A5/fr not_active Expired
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4306921A (en) | 1978-03-16 | 1981-12-22 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| US4384892A (en) | 1978-03-16 | 1983-05-24 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| US4404024A (en) | 1978-03-16 | 1983-09-13 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| US4447264A (en) * | 1978-03-16 | 1984-05-08 | Kanto Denka Kogyo Co., Ltd. | Production of magnetic powder |
| US4287233A (en) | 1979-02-13 | 1981-09-01 | Basf Aktiengesellschaft | Manufacture of acicular cobalt-containing magnetic iron oxide |
| US4296149A (en) | 1979-02-13 | 1981-10-20 | Basf Aktiengesellschaft | Manufacture of acicular cobalt-containing magnetic iron oxide |
| DE3245635A1 (en) * | 1981-12-09 | 1983-06-16 | Japan Metals & Chemicals Co., Ltd., Tokyo | Process for producing a ferromagnetic oxide |
| CN113106484A (en) * | 2021-04-07 | 2021-07-13 | 西南大学 | Hydrothermal preparation method of novel photo-anode based on alpha-type iron oxide vermicular nano-structure array, product and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| NL7004295A (en) | 1970-11-10 |
| BE750031A (en) | 1970-10-16 |
| DE2022013A1 (en) | 1970-11-19 |
| FR2047369A5 (en) | 1971-03-12 |
| DE2022013C2 (en) | 1982-11-25 |
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