Mixing kinetics and write-once optical recording characteristics of Sb/Se bilayer films

Abstract

Bilayer Sb/Se films are irradiated with 12 ns pulses from an ArF laser (extended areas) and from a focused Ar+ laser (micron-sized areas). Real-time reflectivity measurements are used to determine if the process occurs within the solid or liquid phase and the transformation time, in addition to measure the optical contrast and the medium sensitivity. Transmission electron microscopy is used to analyze the structure of the transformed areas and the medium resolution. The results show that mixing is initiated by preferential melting at the gram boundaries and an amorphous phase is produced upon irradiation a high energy densities. Finally, the characteristics of the mixing process in Sb/Se films as a write-once optical recording mechanism are discussed in terms of the sensitivity and resolution of the recorded spots and the time required for recording.