Near Kohn anomalies in the phonon dispersion relations of lead chalcogenides

Kilian, Ondrej; Allan, Guy; Wirtz, Ludger

Type de document :

Compte-rendu et recension critique d'ouvrage

DOI :

10.1103/PhysRevB.80.245208

Titre :

Near Kohn anomalies in the phonon dispersion relations of lead chalcogenides

Auteur(s) :

Kilian, Ondrej [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Allan, Guy [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Wirtz, Ludger [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]

Titre de la revue :

Physical Review B: Condensed Matter and Materials Physics (1998-2015)

Pagination :

245208-1-7

Éditeur :

American Physical Society

Date de publication :

2009

ISSN :

1098-0121

Discipline(s) HAL :

Sciences de l'ingénieur [physics]

Résumé en anglais : [en]

We present ab-initio phonon dispersion relations for the three lead chalcogenides PbS, PbSe, and PbTe. The acoustic branches are in very good agreement with inelastic neutron-scattering data and calculations of the specific ...
Lire la suite >We present ab-initio phonon dispersion relations for the three lead chalcogenides PbS, PbSe, and PbTe. The acoustic branches are in very good agreement with inelastic neutron-scattering data and calculations of the specific heat give good agreement with experimental data. The pronounced minimum of the transverse optical branch at Γ due to the near-ferroelectricity of the lead chalcogenides is qualitatively reproduced. In addition, we find a pronounced dip in the longitudinal optical branch at Γ. This dip was previously explained as the effect of “free carriers” (due to the presence of impurities). The calculations demonstrate that it persists also in the case of pure lead chalcogenides. We explain the dip as a ”near Kohn anomaly” which is associated with the small electronic band-gap at the high-symmetry point LLire moins >

Langue :

Anglais

Vulgarisation :

Non

Collections :