38 research outputs found
Ab Initio Phonon Dispersions for PbTe
We report first principles calculations of the phonon dispersions of PbTe
both for its observed structure and under compression. At the experimental
lattice parameter we find a near instability of the optic branch at the zone
center, in accord with experimental observations.This hardens quickly towards
the zone boundary. There is also a very strong volume dependence of this mode,
which is rapidly driven away from an instability by compression. These results
are discussed inrelation to the thermal conductivity of the material.Comment: 3 figures; typos corrected. Figure 1 replaced to correct labe