Phase-change recording material and information recording medium
View Patent ↗A phase-change recording material on which high velocity recording/erasing is possible, which provides excellent recording signal characteristics, which provides a high storage stability of the recording signals, with which the change in the reflectivity of the recorded signals is small even after a long term storage, and which provides excellent recording signal characteristics even if overwriting is carried out again, and an information recording medium employing the above material, are provided. It is characterized by containing as the main component a composition represented by Ge x (In w Sn 1-w ) y Te z Sb 1-x-y-z (wherein the Sb content is higher than any one of the Ge content, the In content, the Sn content and the Te content, and x, y, z and w representing atomicity ratios satisfy (i) 0≦x≦0.3, (ii) 0.07≦y-z, (iii) wxy-z≦0.1, (iv) 0<z, (v) (1−w)xy≦0.35 and (vi) 0.35≦1-x-y-z).
1. A phase-change recording material characterized by containing a composition represented by the following formula (1) as the main component:
Ge x (In w Sn 1-w ) y Te z Sb 1-x-y-z (1)
(wherein the Sb content is higher than any one of the Ge content, the In content, the Sn content and the Te content, and x, y, z and w representing atomic ratios, satisfy the following (i) to (vi):
(i) 0≦x≦0.3
(ii) 0.07≦y-z
(iii) wxy-z≦0.1
(iv) 0<z
(v) (1-w)xy≦0.35
(vi) 0.35≦1-x-y-z).
2. The phase-change recording material according to claim 1 , wherein in the formula (1), x further satisfies 0<x.
3. The phase-change recording material according to claim 1 , wherein in the formula (1), x further satisfies x≦0.1.
4. The phase-change recording material according to claim 1 , wherein in the formula (1), w further satisfies 0<w<1.
5. The phase-change recording material according to claim 1 , wherein in the formula (1), z further satisfies 0.1<z.
6. The phase-change recording material according to claim 1 , wherein of the above information recording material, the crystalline state corresponds to a non-recorded state, and the amorphous state corresponds to a recorded state.
7. An information recording medium having a recording layer, characterized in that the above recording layer contains a composition represented by the following formula (1) as the main component:
Ge x (In w Sn 1-w ) y Te z Sb 1-x-y-z (1)
(wherein the Sb content is higher than any one of the Ge content, the In content, the Sn content and the Te content, and x, y, z and w representing atomic ratios, satisfy the following (i) to (vi):
(i) 0≦x≦0.3
(ii) 0.07≦y-z
(iii) wxy-z≦0.1
(iv) 0<z
(v) (1-w)xy≦0.35
(vi) 0.35≦1-x-y-z).
8. The information recording medium according to claim 7 , wherein in the formula (1), x further satisfies 0<x.
9. The information recording medium according to claim 7 , wherein in the formula (1), x further satisfies x≦0.1.
10. The information recording medium according to claim 7 , wherein in the formula (1), w further satisfies 0<w<1.
11. The information recording medium according to claim 7 , wherein in the formula (1), z further satisfies 0.1<z.
12. The information recording medium according to claim 7 , wherein of the above information recording medium, the crystalline state corresponds to a non-recorded state, and the amorphous state corresponds to a recorded state.
13. The information recording medium according to claim 7 , wherein the information recording medium is an optical information recording medium, on which recording is carried out by a laser beam.
14. The information recording medium according to claim 13 , wherein the optical information recording medium has a protective layer A in contact with the recording layer, and the protective layer A contains a metal oxysulfide and/or a metal nitride.
15. The information recording medium according to claim 14 , wherein the metal oxysulfide is an oxysulfide of yttrium, and the metal nitride is a nitride of an alloy containing germanium as the main component.
16. The information recording medium according to claim 14 , wherein the protective layer A is formed in contact with each side of the recording layer.
17. The information recording medium according to claim 14 , wherein the above protective layer A is formed in contact with the side of the recording layer from which a laser beam enters, and the above protective layer A has a thickness of at most 50 nm.
18. The information recording medium according to claim 14 , wherein the protective layer A is formed in contact with the side of the recording layer from which a laser beam enters, and further, a protective layer B is formed on the side opposite to the above recording layer in contact with the protective layer A, and the total thickness of the thickness of the protective layer A and the thickness of the protective layer B is at most 50 nm.
19. The information recording medium according to claim 14 , wherein the recording layer has a thickness of at least 5 nm and at most 15 nm.
20. The information recording medium according to claim 13 , wherein the optical information recording medium further has a reflective layer, and the reflective layer contains Ag as the main component.