LOW.FREQUENCY LATTICE VIBRATIONS OF delta-GaSe COMPARED TO epsilon- AND gamma-POLYTYPES

Alain Polian (1, 2) , K. Kunc (3, 2) , Arno Kuhn (4)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 LPS - Laboratoire de Physique des Solides
3 Max-Planck-Institut für Festkörperforschung
4 UPMC - Université Pierre et Marie Curie - Paris 6

Raman spectra of the new polytype 5-GaSe are given in the low-frequency region (co < 60 cm-1) and their relation to lattice vibrations of the simpler polytypes 3', e is discussed. A simple lattice dynamical model is used to describe the phonon modes in all 3 modifications. First observation of Davydov splitting in e-GaSe is reported. Particular weakness of one component of this doublet is shown to be a consequence of the specific "molecular" nature of layer crystal.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Alain Polian, K. Kunc, Arno Kuhn. LOW.FREQUENCY LATTICE VIBRATIONS OF delta-GaSe COMPARED TO epsilon- AND gamma-POLYTYPES. Solid State Communications, 1976, 19, pp.1079 - 1082. ⟨hal-01820693⟩