| abstract |
(57) [Problem] To provide a phase change optical disk capable of recording and reproducing repeatedly. A high-density phase change disk used as a DVD-RAM includes a reflective layer made of a noble metal such as copper (Cu), silver (Ag), and gold (Au) having high thermal conductivity, reflectance, and melting point. Accordingly, the number of overwrites is greatly improved as compared with the existing phase change optical disk having an Al reflective layer, and the cross erase phenomenon in which data recorded on a track adjacent to a track to be recorded is erased is significantly reduced. . |