Completely Erasable Phase Change Optical Disc II: Application of Ag-In-Sb-Te Mixed-Phase System for Rewritable Compact Disc Compatible with CD-Velocity and Double CD-Velocity

Aiming to obtain a rewritable compact disc (CD-rewritable) with high performance at both CD-velocity (CD1X) and double CD-velocity (CD2X), the phase change optical disc with the Ag-In-Sb-Te system has been developed. In the one-pass overwriting mode with eight-to-fourteen modulation, high carrier-to-noise ratio, wide power margin and high erase ratio have been obtained at both velocities. As for stability, we acquired a satisfactory result in the read-out test of 10⁶ cycles with read power of 1.5 mW. We conclude that the phase change optical disc with the Ag-In-Sb-Te system is suitable for use at both CD1X and CD2X. Furthermore, the phase change process of the Ag-In-Sb-Te system has also been investigated. The chemical structure of the Ag-In-Sb-Te system in its ordered state was found to be (Ag-Sb-Te)_x(In_1-ySb_y)_1-x.