LATTICE DYNAMICS OF WURTZITE SEMICONDUCTORS GaN AND AlN

The lattice dynamics of wurtzite GaN and AlN is studied within the framework of a rigid-ion model. Short-range interactions up to the third nearest neighbors are described by using a valence-force-field potential and the long-range Coulomb interactions between ions are calculated via an Ewald summation. Phonon dispersion curves, density of states and specific heats are presented.