| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a double layer information recording medium which has high reliability of recorded data and excellent durability when data are repeatedly recorded. <P>SOLUTION: The information recording medium comprises a first and second recording layer formed by phase change material including Bi, Ge and Te, and the first recording layer is disposed at a position nearer to an incident side of a laser beam than the second recording layer. The composition of Bi, Ge, and Te in the second recording layer is in the composition range enclosed by composition points B2, C2, D2, D6, C6, and B6 on a triangle composition diagram of Bi, Ge, and Te, and a difference α-δ between the composition α of Bi in the first recording layer and the composition δ of Bi in the second recording layer is within -1.0 to 3.0 at.%. <P>COPYRIGHT: (C)2009,JPO&INPIT |
