| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a large decrease in recording characteristics even by repeating overwriting many times by reducing jitter at front and rear ends of a recording mark in the case of recording in a mark edge type in a phase change type optical recording medium. SOLUTION: A recording layer is constituted by a thin film containing composition including Ge, Te, Sb, Bi and N. The composition of the Ge, Te and Sb in the film falls within a range inside a parallelogram on line of a parallelogram having four points A, B, C, D of a triangular graph as vertexes, where atomic ratio of Ge, Te and Sb is Ge:Te:Sb: =x:y:z(x+y+z=1). The content of Bi satisfies a formula of 0.1<= w/(z(1-w))<=1.0, where atomic ratio of Gex , Tey , Sbz and Bi is Gex Tey Sbz :Bi =(1-w):w. |
