Thermopower in the hopping conductivity region: Transition from Mott’s to Zvyagin’s formula

  • S. V. Demishev
  • M. V. Kondrin
  • A. A. Pronin
  • N. E. Sluchanko
  • N. A. Samarin
  • A. G. Lyapin
  • G. Biscupski
Condensed Matter

DOI: 10.1134/1.567803

Cite this article as:
Demishev, S.V., Kondrin, M.V., Pronin, A.A. et al. Jetp Lett. (1998) 68: 842. doi:10.1134/1.567803

Abstract

Zvyagin’s theoretical calculation for the thermopower due to electron hops is confirmed experimentally. It is shown for a-GaSb that in the Mott-law region the thermopower is a square-root function of temperature \(\sqrt T \), and at low temperatures T<25 K the hopping contribution to the Seebeck coefficient dominates. A temperature increase induces a transition to conductivity due to hops between nearest centers. The thermopower in this regime is described by the Mott formula modified so as to take into account the higher-order derivatives of the density of states. It is established that in a-GaSb the thermopower at temperatures 4.2 K <T<300 K can be represented as a superposition of two contributions: a hopping contribution and an anomalous contribution presumably due to phonon drag. A model is proposed which gives a quantitative description of the temperature dependence of the hopping thermopower on the basis of a single setup parameters characterizing the density of localized states.

PACS numbers

72.20.Fr 72.20.Pa 

Copyright information

© MAIK "Nauka/Interperiodica" 1998

Authors and Affiliations

  • S. V. Demishev
    • 1
  • M. V. Kondrin
    • 1
  • A. A. Pronin
    • 1
  • N. E. Sluchanko
    • 1
  • N. A. Samarin
    • 1
  • A. G. Lyapin
    • 2
  • G. Biscupski
    • 3
  1. 1.Institute of General PhysicsRussian Academy of SciencesMoscowRussia
  2. 2.Institute of High-Pressure PhysicsRussian Academy of SciencesTroitsk, Moscow RegionRussia
  3. 3.Université des Sciences et Technologies de LilleLilleFrance