Patent ID: 8075974

Claim:
An optical recording medium comprising: a first protective layer, a recording layer, a second protective layer, and a reflective layer formed in this order as viewed from the side of laser beam irradiation for recording and reproducing wherein, the recording layer comprises a phase-change material represented by any one of the following Composition Formula (1-1), Composition Formula (1-2), and Composition Formula (1-3); and the second protective layer comprises at least one selected from a material represented by the following Composition Formula (2), and a material represented by the following Composition Formula (3), In α1 Sb β1 X1 γ1 Composition Formula (1-1) where X1 is at least one selected from Ge, Te, Zn, and Mn; α1, β1, and γ1 respectively represent an atomic ratio, where 0.10≦α1≦0.25, 0.65≦β1≦0.80, and 0.04≦γ1≦0.15, Ga α2 Sb β2 Sn γ2 Ge δ2 X2 ∈2 Composition Formula (1-2) where X2 is at least one selected from Te, Zn, Mn, and In; α2, β2, γ2, δ2, and ∈2 respectively represent an atomic ratio, where 0.04≦α2≦0.09, 0.56≦β2≦0.79, 0.05≦γ2≦0.30, 0.03≦δ2≦0.19, and 0≦∈2≦0.09, Mn α3 Sb β3 Sn γ3 Ge δ3 X3 ∈3 Composition Formula (1-3) where X3 is at least one selected from Te, In, Zn, and Bi; α3, β3, γ3, δ3, and ∈3 respectively represent an atomic ratio, where 0.04≦α3≦0.09, 0.56≦β3≦0.79, 0.05≦γ3≦0.29, 0.03≦δ3≦0.23, and 0≦∈3≦0.09, ZnO—Al—Y[(100−α4−β4):α4:β4] Composition Formula (2) where Y is at least one selected from Mn, Ge, and Ti; α4 and β4 respectively represent a percent by mass, where 0.5≦α4≦10.0, and 0≦β4≦25.0, ZnO—Al 2 O 3 —Z[(100−α5−β5):α5:β5] Composition Formula (3) where Z represents any one of an Mn oxide, a Ge oxide, a Ti oxide, and a mixture thereof; α5 and β5 respectively represent a percent by mass, where 0.5≦α5≦10.0, and 0≦β5≦30.0.