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EP0168046A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Magneto-optical recording material

Assignee: Hitachi Ltd
•
Filing: 1985-07-10
•
Granted: —
•
Expires: 2005-07-10
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Abstract

Abstract Disclosed is a magneto-optical recording material whose composition formula is indicated by (Co 1-a Ma) 100-y R y where M denotes at least one element selected from the group consisting of elements of the platinum group and Fe, Ni, Nb, Cu, Ag, Al, B, Si and Ge; R denotes either at least two elements selected from the group consisting of Tb, Sm, Gd, Dy, Ho and Y or a single element selected from the group consisting of Tb, Gd, Dy and Ho; the value a satisfies 0 < a ≦ 0.5, while the value y satisfies 14 ≦ y ≦ 36 in terms of atomic percent; the material being substantially amorphous. A perpendicularly magnetized amorphous film made of this material is excellent in thermal stability, corrosion resistance etc., and affords a greater read output-to-noise ratio (C/N).

Inventors

  • 👤 Shinji Takayama
  • 👤 Toshio Niihara
  • 👤 Katsuhiro Kaneko
  • 👤 Yutaka Sugita

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 13:56
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/16; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 104 words
A magneto-optical recording material whose composition formula is indicated by where M denotes at least one element selected from the group consisting of elements of the platinum group and Fe, Ni, Nb, Cu, Ag, Al, B, Si and Ge; R denotes either of at least two elements selected from the group consisting of Tb, Sm, Gd, Dy, Ho and Y and a single element selected from the group consisting of Tb, Gd, Dy and Ho; the value a satisfies 0 < a < 0.5, while the value y satisfies 14 < y < 36 in terms of atomic percent; said material being substantially amorphous.
Claim 2
Dependent Claim 104 words
A magneto-optical recording material whose composition formula is indicated by where M denotes at least one element selected from the group consisting of elements of the platinum group and Fe, Ni, Nb, Cu, Ag, Al, B, Si and Ge; R denotes either of at least two elements selected from the group consisting of Tb, Sm, Gd, Dy, Ho and Y and a single element selected from the group consisting of Tb, Gd, Dy and Ho; the value a satisfies 0 < a < 0.5, while the value y satisfies 14 < y < 36 in terms of atomic percent; said material being substantially amorphous.
Claim 3
Dependent Claim 15 words
A magneto-optical recording material as defined in Claim 1, wherein the constituent R contains Tb.
Claim 4
Dependent Claim 22 words
A magneto-optical recording material as defined in Claim 1 or 2 , wherein said value y satisfies 22 ≦ y < 29.
Claim 5
Dependent Claim 23 words
A magneto-optical recording material as defined in any of Claims 1 to 3, wherein the constituent M contains at least the Fe element.

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