HX-PES study of rewritable phase-change recording media

Abstract

ABSTRACT The influence of the interface layer to the chemical and electronic states of a phase-change recording material, GeBiTe (GBT) alloy, used in the high-spe ed rewritable HD DVD media was investigated for the first time using the hard x-ray photoelectron spectroscopy (HX-PES). The density of states (DOS) for the valence band of the amorphous state without an interface layer was smaller than that of the crystalline state. The band-edge energy of the amorphous state without an interface layer was lower by about 0.5 eV than that of the crystalline state. On the other ha nd, the DOS and the band-edge energy of the amorphous state of GBT with interface layers were almost same as that of the crystalline state, respectively. This result may lead to almost the same career density for electrical conduction for the crystal as the amorphous, which is totally unexpected thus ve ry interesting b ecause the atomic arrangeme nts should differ from each other. We speculate that this effect is a factor for a high-speed crystallization. Keywords: Phase-change recording media, interface layer, rewritable HD DVD, GeBiTe (GBT) alloy, fast overwrite, high data transfer rate, high-speed rewritable media, HX-PES, density of state (DOS), valence band