Dynamic theory of crystallization in Ge2Sb2.3Te5 phase-change optical recording media

We develop a theory of the crystallization dynamics of Ge2Sb2.3Te5 thin films that shows good qualitative agreement with experimental reflectivity results from a two-laser static tester. The theory is adapted from the nucleation theory of liquid droplets from supersaturated vapor and elucidates the physics underlying the amorphous-to-crystalline phase transformation under short-pulse excitation. In particular, the theory provides a physical picture in which crystalline islands, or basic embryos, are thermally activated in the amorphous material and subsequently grow as stable nuclei are formed. (C) 2000 Optical Society of America OCIS codes: 210.0210, 210.4590, 210.4770, 210.4810.