Reversible Optical Recording Media with Ga-Se-Te System

Reversible optical change in a thin film system of parylene/Te z (Ga x Se 1- x ) 1- z (0.6 ≤ z ≤0.9, 0 ≤ x ≤0.3)/parylene structure has been studied by measuring reflectance of an optical system focused laser beam to micron-sized spots. Retention time of data written by laser beam is examined under conditions of 50°C and 70% relative humidity. By surface observation with a high resolution SEM, it is found that, as the amount of Ga increases, the retention time is maximal, corresponding to the maximum diameters of microcrystallites with a cylindrical structure.