PHASE TRANSITION TYPE OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To attain high writing and erasing sensitivity and to improve signal intensity by incorporating a specific ratio of Se into an optical recording layer contg. Te-Bi at a specific compsn. ratio. CONSTITUTION:The optical recording layer consisting of a thin alloy film is formed via a transparent underlying layer 2 on a transparent substrate 1 and further a transparent protective layer 4 is provided thereon. The Te and Bi as well as the Se are mainly incorporated into this optical recording layer. The ratio of the atom. contents of the Te and the Bi is specified to 45:55-65:35 and the Se is incorporated therein at 2-20at.%. The alloy film of the Te-Bi is chemically stable over a wide compsn. range. Generation of phase sepn. is obviated in spite of repetition of writing and erasing and the impairment of the initial characteristics is obviated.