Phase change in Ge2Sb2Te5 films investigated by coherent phonon spectroscopy

摘要

Amorphous and crystalline phases of Ge2Sb2Te5 films are investigated by coherent phonon spectroscopy. By heating amorphous films above specific temperatures, the coherent phonon signatures exhibit pronounced changes due to the crystallization of the amorphous phase into a cubic lattice and the transition from the cubic to a hexagonal crystal structure. The phonon modes observed are identified by comparison with coherent phonon spectra of the binary Sb2Te3 and GeTe constituents. (C) 2000 American Institute of Physics. S0003-6951(00)03439-2. References: 15