PURPOSE: To obtain a phase transition type optical recording medium which has the reflectance and signal modulation degree compatible to the CD standard and enables recording at the same line speed as the reproducing speed of the CD standard.
CONSTITUTION: This phase transition type optical recording medium consists of a substrate 1 and a metal layer 2, first protective layer 3, recording layer 4, second protective layer 5 and reflecting layer 6 formed on the substrate. Recording is performed by causing phase transition from the crystal state to the amorphous state of the recording layer 4. The recording layer 4 consists of a Ge-Te-Sb-Se recording material and the average composition in the film thickness direction of the recording layer 4 satisfies Ge≥40 atomic % and Sb+Se≤25 atomic %. The recording layer 4 has ≥70 % reflectance for reproducing light in either the crystal state or amorphous state and has <40% reflectance in the other state. As for the metal layer 2, an AuCo alloy is used.
IKARI YOSHIHIRO
YASUI TOSHIAKI
OTA NORIO
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