Phonon Properties and Low Thermal Conductivity of Phase Change Material with Superlattice-Like Structure

Based on the Parlinsk-Li-Kawasoe method and density function theory, the phonon properties of some phase change memory materials are calculated. Thermal conductivities are acquired from our calculation, and they are in reasonable agreement with our experimental measurements. Phonon dispersion curve, mismatch between phonon density of states (DOS), partial density of states (PDOS) at interfaces, and thermal conductivities are studied. The results show that the low phonon group velocity and the thermal resistance at interfaces result in the low thermal conductivity of the GeTe/Sb2Te3 superlattice-like material, making it the best choice for phase change memory. (c) 2012 The Japan Society of Applied Physics