| 摘要 |
PURPOSE:To obtain a phase changing optical information record medium with good quality by providing a record layer having a specific composition as a main component and formed by a specific multiphase. CONSTITUTION:A main component of a record layer is represented by an expression and constituted of a multiphase of xGeTe.(1-x)Sb2Te3 phase and M phase. The record layer is in a multiphase state comprising a phase of GeTe-SB2Te3 and a single phase of Sb and/or Bi or a phase of alloy. Now, GeTe-Sb2Te3 has three crystal phases GeSb4Te7, GeSb2Te4, and GeSb2Te5. It is well known that a melting point becomes high with increase of the composition of GeTe. In this case, recording or erasing is performed by changing a reflection coefficient with phase change of crystal and non-crystal quality. In the record layer, the single phase of Sb or Bi represented by M in the expression or the allay phase is included in such a phase of SeTe-Sb2Te. As a result, a remarkably high erasing ratio will be obtainable. |
