GB665554A - Improvements in or relating to a method of making magnetic material - Google Patents

Improvements in or relating to a method of making magnetic material

Info

Publication number
GB665554A
GB665554A GB2238748A GB2238748A GB665554A GB 665554 A GB665554 A GB 665554A GB 2238748 A GB2238748 A GB 2238748A GB 2238748 A GB2238748 A GB 2238748A GB 665554 A GB665554 A GB 665554A
Authority
GB
United Kingdom
Prior art keywords
magnetic
hydrogen
ferric oxide
mixed
air
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
GB2238748A
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.)
Armour Research Foundation
Original Assignee
Armour Research Foundation
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 Armour Research Foundation filed Critical Armour Research Foundation
Priority to GB2238748A priority Critical patent/GB665554A/en
Publication of GB665554A publication Critical patent/GB665554A/en
Expired legal-status Critical Current

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
    • 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
    • G11B5/70647—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 with a skin
    • 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
    • G11B5/70678—Ferrites
    • G11B5/70684—Ferro-ferrioxydes

Landscapes

  • Health & Medical Sciences (AREA)
  • Dermatology (AREA)
  • General Health & Medical Sciences (AREA)
  • Hard Magnetic Materials (AREA)

Abstract

A magnetic material suitable for the production of coated or impregnated record tapes &c. is produced by reducing an initially non-magnetic ferric oxide having a particle size not exceeding six microns in its greatest dimension at 400-1000 DEG F. Reduction may be effected by hydrogen, carbon monoxide, sulphur, sodium acetate, pyrogallol &c. Hydrated acicular Fe2O3 or anhydrous ferric oxide may be employed. Water vapour may be mixed with the hydrogen employed. The reduced black oxide may be reoxidized in the presence of oxygen at 300-900 DEG F to yield magnetic g -ferric oxide. In an example, Fe2O, H2O nuclei are prepared by agitating mixed solutions of caustic soda and ferrous sulphate for 17 hours in the presence of air, and the nucleating material is then mixed with ferrous sulphate solution and scrap iron, and air bubbled through at 140 DEG F. The dried material is then tumbled in hydrogen at 750 DEG F till nearly black. The temperature is finally reduced to less than 70 DEG F before air is readmitted. The magnetic properties of the various products are indicated.
GB2238748A 1948-08-25 1948-08-25 Improvements in or relating to a method of making magnetic material Expired GB665554A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2238748A GB665554A (en) 1948-08-25 1948-08-25 Improvements in or relating to a method of making magnetic material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2238748A GB665554A (en) 1948-08-25 1948-08-25 Improvements in or relating to a method of making magnetic material

Publications (1)

Publication Number Publication Date
GB665554A true GB665554A (en) 1952-01-23

Family

ID=10178561

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2238748A Expired GB665554A (en) 1948-08-25 1948-08-25 Improvements in or relating to a method of making magnetic material

Country Status (1)

Country Link
GB (1) GB665554A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4311684A (en) * 1979-05-11 1982-01-19 Tdk Electronics Co., Ltd. Process for producing iron oxide containing magnetite

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4311684A (en) * 1979-05-11 1982-01-19 Tdk Electronics Co., Ltd. Process for producing iron oxide containing magnetite

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