PHONONS IN TMTE

In TmTe single crystals the optical reflectivity has been measured dow n to 1 meV at 300 K and at 10 K. TO and LO phonon frequencies could be determined as well as the optic and static dielectric constant. The R aman scattering has also been performed which measures a weighted phon on density of states. The dispersion of the LA and TA branches has bee n determined from the sound velocities and in [1 1 1] direction the co mplete phonon dispersion has been evaluated. (C) 1998 Published by Els evier Science Ltd. All rights reserved.