Sony Corporation

Nobuhiro Saito

Minoru Kikuchi

Fuminori Takase

Yoshihiro Akimoto

Masaki Kagawa

Masaki Takenouchi

Noriko Kikuchi

Optical disc having specified track pitch, push-pull signal, and cross-track signal

Optical Disc

A phase-change optical disc has a recording layer formed from a phase-change material switchable between a crystalline state and an amorphous state. The recording layer is illuminated signal-wise by a light is focused onto the recording layer to change the phase thereof from crystalline to amorphous, to thereby write an information signal onto the recording layer. The phase-change material contains a GeSbTe alloy. The recording layer is formed by sputtering in an Ar gas atmosphere containing at least either N,or O,gas or both. The optical recording medium exhibits improved durability after repeated recording and maintains a stable and good write/read characteristic even after repeated cycles of signal recording.

Optical recording medium and method of manufacturing the same

Anticorrosion magneto-optical recording medium is disclosed. The magneto-optical recording medium comprises a recording layer formed of an amorphous alloy of transition metal and rare-earth metal such as Tb--Fe or Tb--FeCo. On the recording layer, there are provided a transition metal layer such as FeCoCr alloy layer and a rare-earth metal layer such as Tb, in this order. Selective oxidation of rare-earth metal in the recording layer is effectively avoided by the existance of the layers.

Magneto-optical recording medium

Growing community of inventors

Miyagi, Japan

Nobuhiro Saito