Lattice dynamics and specific heat of alpha-GeTe: Theoretical and experimental study

Shaltaf, R.;Gonze, Xavier;Cardona, M.;Kremer, René;Siegle, G.
(2009) Physical review. B, Condensed matter and materials physics — Vol. 79, n° 7, p. 075204 : 1-7 (2009)

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Authors
  • Shaltaf, R.UCLouvain
    Author
  • Gonze, Xavierorcid-logoUCLouvain
    Author
  • Cardona, M.
    Author
  • Kremer, RenéUCLouvain
    Author
  • Siegle, G.
    Author
Abstract
We extend recent ab initio calculations of the electronic band structure and the phonon-dispersion relations of rhombohedral GeTe to calculations of the density of phonon states and the temperature-dependent specific heat. The results are compared to measurements of the specific heat. It is discovered that the specific heat depends on hole concentration, not only in the very low temperature region (Sommerfeld term) but also at the maximum of C-p/T-3 (around 16 K). To explain this phenomenon, we have performed ab initio lattice-dynamical calculations for GeTe rendered metallic through the presence of a heavy-hole concentration (p similar to 2x10(21) cm(-3)). They account for the increase observed in the maximum of C-p/T-3.
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Citations

Shaltaf, R., Gonze, X., Cardona, M., Kremer, R., & Siegle, G. (2009). Lattice dynamics and specific heat of alpha-GeTe: Theoretical and experimental study. Physical review. B, Condensed matter and materials physics, 79(7), 075204 : 1-7. https://doi.org/10.1103/PhysRevB.79.075204 (Original work published 2009)