| 摘要 |
PURPOSE:To increase the reflectivity in recording and erasing and to preserve the recording stably over a long period of time by using a material having a specific compsn. to form the recording layer of the rewritable phase change type optical memory medium. CONSTITUTION:The recording layer of the rewritable phase change type optical memory medium is constituted of a ternary alloy consisting of In-Sb-Te or quaternary alloy consisting of In-Sb-Te-Se and the ratios of the metal elements are limited as follows: a=4-28atomic%, b=17-4atomic%, content c of M (Te or Te+Se)=46-53atomic%. The erasing time is reduced to <=0.2musec if the (a), (b) are limited to the above-mentioned values. The contrast ratio increases to >=20% if the (c) is limited to the above-mentioned value. In addition, the number of repetition of recording and erasing is increased and the recording is preserved stably over a long period of time. |
