Magnetic recording medium with a zinc cobalt oxide non-magnetic substrate containing nickel or manganese

• US 5,026,614 A
• Filed: 02/24/1989
• Issued: 06/25/1991
• Est. Priority Date: 02/25/1988
• Status: Expired due to Fees

• Current Assignee: Japan Energy Corporation (ENEOS Holdings, Inc.)
• Original Assignee: Nippon Mining & Metals Company Limited (JX Holdings Incorporated)
• Inventors: Nagase, Ryuichi, Saito, Kazuhiro, Hosaka, Hiroshi, Itoh, Eiji, Nagai, Hihumi
• Primary Examiner(s): Cashion, Jr., Merrell C.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/314,738
• Time in Patent Office: 851 Days
• Field of Search: 428/64, 428/658, 428/659, 428/680, 428/694, 428/900, 428/469
• US Class Current: 428/658
• CPC Class Codes: G11B 5/147 with cores being composed of metal sheets, i.e. laminated cores with cores composed of isolated magnetic layers, e.g. sheets in thin films G11B5/31
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/1157 Substrate composition
• CPC Class Codes: Y10T 428/12792 Zn-base component
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12944 Ni-base component

Abstract

A non-magnetic substrate used for a magnetic head comprising a pair of non-magnetic substrates, and a magnetic layer structure sandwiched between the pair of non-magnetic substrates. The magnetic layer structure is comprised, of alternately laminated magnetic layers and intermediate insulating layers. The invention discloses for the substrate material a composition expressed by Zn_x M_y Co_2-x-y O₂, with the proviso that M is Mn or Ni, 0≦x≦0.4, 0.4≦y≦1.0, 0.8≦x+y≦1.0, or CO_x Ni_2-x O₂, with the proviso that 0.2≦x≦1.8, and having a rock-salt structure.

Claims

1. A non-magnetic substrate for vapor-depositing a magnetic layer thereon, said substrate having a composition expressed by Zn_x M_y Co_2-x-y O₂, wherein that M is selected from the group consisting of Mn and Ni, and 0≦

x≦

0.4, 0.4≦

y≦

1.0, 0.8≦

x+y≦

1.0, and said substrate has a rock-salt structure.

3. A non-magnetic substrate according to claim 1 or 2, wherein at least one oxide selected from the group consisting of MnO, TiO₂, Al₂ O₃, and CaO, is included in a ratio of from 0.1 to 5 wt %.

2. A non-magnetic substrate, having a composition expressed by Co_x Ni_2-x O₂, wherein that 0.2≦

x≦

1.8, and said substrate has a rock-salt structure.

4. A magnetic layer structure comprising:

a magnetic layer vapor deposited on a non-magnetic substrate, wherein said substrate has a composition expressed by Zn_x M_y Co_2-x-y O₂, wherein M is selected from the group consisting of Mn and Ni, 0≦

x≦

0.4, 0.4≦

y≦

1.0, 0.8≦

x+y≦

1.0, and said substrate has a rock-salt structure.

8. A magnetic layer structure according to claim 4, 5, 6, or 7, wherein at least one oxide selected from the group consisting of MnO, TiO₂, Al₂ O₃, and CaO is included in a ratio of from 0.1 to 5 wt % in the substrate.

9. A magnetic layer structure according to claim 4, 5, 6, or 7, wherein said magnetic layer is from 1 to 20 μ

m thick.

6. A magnetic layer structure comprising:

a magnetic layer vapor deposited on a non-magnetic substrate, wherein said substrate has a composition expressed by Co_x Ni_2-x O₂, wherein 0.2≦

x≦

1.8, and said substrate has a rock-salt structure.

5. A magnetic layer structure according to claim 6, wherein said magnetic layer is a magnetic alloy layer of Fe--Si--Al alloy.

7. A magnetic layer structure according to claim 6, wherein said magnetic layer is a magnetic alloy layer of Fe--Si--Al alloy.