Magneto-optical recording medium
AssigneeTeijin Limited
InventorsMasahiko Sekiya, Kiyoshi Chiba
Life of this patent
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Abstract
A magneto-optical recording medium having an improved durability or reliability is obtained by providing a protecting layer of an alloy of titanium with one or more of chromium, rhenium and tantalum. This titanium alloy protecting layer has an improved resistance to oxygen, water, chlorine, and acids, etc. and provides an improved resistance to the environment and attacks from the synthetic resin substrate or other layers constituting the medium, such as a dielectric layer and a reflecting layer.
Claims18
A magneto-optical recording medium, comprising:
- a substrate
- a magneto-optical recording layer above the substrate;
- and
- a first metal protecting layer over the magneto-optical recording layer, the first metal protecting layer being made of a titanium alloy wherein said titanium alloy comprises at least one element of chromium and tantalum and is selected from the group consisting of:
- i) a titanium alloy comprised of only titanium and 10 to 80 atom % chromium and is amorphous or crystalline, when crystalline, said titanium alloy having a lattice spacing of the [002] plane of no greater than 0.23320 nm;
- ii) a titanium alloy comprised of only titanium and from 30 atom % up to 50 atom % tantalum and a lattice spacing of the [002] plane of no greater than 0.2320 nm;
- and
- iii) a titanium alloy comprised of only titanium and from 20 to 80 atom % total of chromium and tantalum and a lattice of spacing of the [002] plane of no greater than 0.2320 nm.
A magneto-optical recording medium having a protective layer which is resistant to permeating and diffusion of at least one of oxygen, water, chlorine or acids, said medium comprising;
- a) a substrate
- b) a magneto-optical recording layer above the substrate;
- c) a first metal protecting layer over the magneto-optical recording layer;
- and
- d) an organic protecting layer above the first metal protecting layer;
- said first metal protecting layer being made of titanium alloy, wherein said titanium alloy comprises at least one element of chromium and tantalum and is selected from the group consisting of:
- i) a titanium alloy comprised of only titanium and 10 to 80 atom % chromium and is amorphous or crystalline, when crystalline said titanium alloy having a lattice spacing of the [002] plane of no greater than 0.2320 nm;
- ii) a titanium alloy comprised of only titanium and from 30 atom % up to 50 atom % tantalum and a lattice spacing of the [002] plane of no greater than 0.2320 nm;
- and
- iii) a titanium alloy comprised of titanium and 20 to 80 atoms % total of chromium and tantalum and a lattice spacing of the [002] plane of no greater than 0.2320 nm.
A magneto-optical recording medium, comprising:
- a substrate;
- a magneto-optical recording layer above the substrate;
- a reflecting layer above the magneto-optical recording layer;
- and
- a first metal protecting layer over the reflecting layer, the first metal protecting layer being made of a titanium alloy wherein said titanium alloy comprises at least one element of chromium and tantalum and is selected from the group consisting of:
- i) a titanium alloy comprised of only titanium and 10 to 80 atom % chromium and is amorphous or crystalline, when crystalline, said titanium alloy has a lattice spacing of the [002] plane of no greater than 0.2320 nm;
- ii) a titanium alloy comprised of only titanium and from 30 atom % up to 50 atom % tantalum and has a lattice spacing of the [002] plane of no greater than 0.2320 nm;
- and
- iii) a titanium alloy comprised of titanium and 20 to 80 atom % total of chromium and tantalum and has a lattice spacing of the [002] plane of no greater than 0.2320 nm.
Dependencies are inferred from the claim text.