GB1479762A - Low coercivity euhedral ferrites and process for making same - Google Patents
Low coercivity euhedral ferrites and process for making sameInfo
- Publication number
- GB1479762A GB1479762A GB2570874A GB2570874A GB1479762A GB 1479762 A GB1479762 A GB 1479762A GB 2570874 A GB2570874 A GB 2570874A GB 2570874 A GB2570874 A GB 2570874A GB 1479762 A GB1479762 A GB 1479762A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mixtures
- alpha
- crystals
- ferric oxide
- oxide
- 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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Magnetic Ceramics (AREA)
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
1479762 Ferrites MINNESOTA MINING & MFG CO 10 June 1974 [11 June 1973] 25708/74 Headings C1J and C1A A mass of discrete magnetically-anisotropic hexagonally-shaped euhedral platelet crystals of a ferrite of one or more of Ba, Sr or Pb is prepared by (a) forming a mixture of particles of (i) ferric oxide or a precursor which converts to ferric oxide upon heating, (ii) at least one oxide or oxide precursor of Ba, Sr or Pb, which precursor converts to the corresponding oxide upon heating, in an amount providing a ferrite of one or more of Ba, Sr and Pb upon reaction with the ferric oxide and (iii) at least one inorganic flux selected from chlorides, bromides, and iodides of sodium and potassium and chlorides of strontium and barium, in an amount greater than 20 wt. per cent of the mixture, (b) heating the mixture to 500‹ to 1100‹ C. whereby the flux melts to a liquid phase for a time sufficient to allow the oxides of Ba, Sr and Pb to dissolve into the liquid phase and to react with the ferric oxide particles to obtain a reaction product comprising the euhedral platelet crystals and (c) separating the crystals from the flux. At least 90% of the crystals have a maximum dimension less than 5 microns and a significant proportion have a distinct hexagonal shape such that the crystals, as measured along their easy axis of magnetization, also exhibit a coercivity of less than 1600 Oersteds and a squareness ratio of not less than 0À50. The ferric oxide in the mixture may be partly substituted by other low solubility oxides, e.g. CoO, FeO and ZnO. The examples describe the production of BaFe 12 O 19 , mixtures of BaFe 12 O 19 and alpha Fe 2 O 3 , mixtures of SrFe 12 O 19 and alpha Fe 2 O 3 , mixtures of Ba 0À9 Sr 0À1 Fe 12 O 19 and alpha Fe 2 O 3 , mixtures of Ba 0À83 Pb 0À17 Fe 12 O 19 and alpha Fe 2 O 3 and mixtures of PbFe 12 O 19 and alpha Fe 2 O 3 from starting mixtures which contain, in addition to the required ingredients, a small amount of Pb 3 O 4 .
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US36850073A | 1973-06-11 | 1973-06-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1479762A true GB1479762A (en) | 1977-07-13 |
Family
ID=23451501
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2570874A Expired GB1479762A (en) | 1973-06-11 | 1974-06-10 | Low coercivity euhedral ferrites and process for making same |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5032498A (en) |
| DE (1) | DE2428004A1 (en) |
| FR (1) | FR2232521A1 (en) |
| GB (1) | GB1479762A (en) |
| IT (1) | IT1013436B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114409392A (en) * | 2022-01-21 | 2022-04-29 | 电子科技大学 | High-remanence-ratio low-loss composite hexagonal ferrite material and preparation method thereof |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2446645A1 (en) * | 1974-09-30 | 1976-04-15 | Shell Int Research | Barium, strontium and lead ferrites - produced by hot pressing mixt. of oxides with minor amts. of fluorides |
| JPS5827212B2 (en) * | 1979-06-08 | 1983-06-08 | 同和鉱業株式会社 | Dry manufacturing method of hexagonal ferrite |
| JPS6015575B2 (en) * | 1980-03-21 | 1985-04-20 | 株式会社東芝 | Method for producing magnetic powder for magnetic recording |
| JPS56124181U (en) * | 1980-02-23 | 1981-09-21 | ||
| JPS6015577B2 (en) * | 1980-05-27 | 1985-04-20 | 株式会社東芝 | Method for producing magnetic powder for magnetic recording |
| JPS5798134A (en) * | 1980-12-11 | 1982-06-18 | Fuji Photo Film Co Ltd | Magnetic recording body |
| GB2173811B (en) * | 1985-04-05 | 1988-08-24 | Tdk Corp | Magnetic recording medium |
| JPS63156018A (en) * | 1986-08-08 | 1988-06-29 | Ube Ind Ltd | Production of ferrite powder |
| JP2532098Y2 (en) * | 1990-10-12 | 1997-04-09 | 株式会社タダノ | Work vehicle detector |
| JPH056744A (en) * | 1991-06-26 | 1993-01-14 | Victor Co Of Japan Ltd | Electromagnetic focusing device |
| US5306592A (en) * | 1992-10-29 | 1994-04-26 | Eastman Kodak Company | Method of preparing electrographic magnetic carrier particles |
| US5268249A (en) * | 1992-10-29 | 1993-12-07 | Eastman Kodak Company | Magnetic carrier particles |
-
1974
- 1974-06-10 IT IT5147674A patent/IT1013436B/en active
- 1974-06-10 JP JP49065880A patent/JPS5032498A/ja active Pending
- 1974-06-10 FR FR7419900A patent/FR2232521A1/fr not_active Withdrawn
- 1974-06-10 DE DE19742428004 patent/DE2428004A1/en active Pending
- 1974-06-10 GB GB2570874A patent/GB1479762A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114409392A (en) * | 2022-01-21 | 2022-04-29 | 电子科技大学 | High-remanence-ratio low-loss composite hexagonal ferrite material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2232521A1 (en) | 1975-01-03 |
| DE2428004A1 (en) | 1975-01-02 |
| JPS5032498A (en) | 1975-03-29 |
| IT1013436B (en) | 1977-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| GB1479762A (en) | Low coercivity euhedral ferrites and process for making same | |
| US2762777A (en) | Permanent magnet and method of making the same | |
| US2715109A (en) | Ferromagnetic ceramic materials with hysteresis loops of rectangular shape | |
| US2565111A (en) | Ceramic magnetic material with a small temperature coefficient | |
| GB1362720A (en) | Flexible permanent magnet | |
| JPS5792527A (en) | Preparation of needle-like ferric oxide | |
| GB1273419A (en) | Process for producing ceramic materials | |
| GB1143448A (en) | Improvements in or relating to manganese-zinc-ferrites | |
| JPS5734022A (en) | Production of magnesium oxide | |
| GB1436228A (en) | Magnetic head and method of making same | |
| GB1496890A (en) | Manufacture of magnetic materials which exhibit exchange anisotropy | |
| GB823971A (en) | Improvements in or relating to ferromagnetic ferrite materials | |
| GB1281112A (en) | A method of preparing catalysts | |
| GB862821A (en) | Improvements in or relating to methods of manufacturing bodies of ferromagnetic materials | |
| JPS56109820A (en) | Manufacture of magnesium hydroxide | |
| GB1060598A (en) | Ferromagnetic cores and processes for the preparation thereof | |
| GB1317250A (en) | Ferrite materials | |
| GB1022969A (en) | Method of producing a permanent magnet material | |
| US4259197A (en) | Process of preparing ferrite powders | |
| GB1256205A (en) | Improvements in and relating to the making of lithium ferrites | |
| JPS59174573A (en) | Oxide magnetic material for permanent magnet | |
| GB1355779A (en) | Lithium titanium bismuth cobalt ferrites | |
| GB1292735A (en) | Method of manufacturing a sintered ferromagnetic ferrite body | |
| SU1733195A1 (en) | Method of producing strontium ferrite powder for magnetoplasts | |
| JPS5580727A (en) | Lithium type ferrite |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |