Adiabatic electron-phonon interaction and high-temperature thermodynamics of A15 compounds.

Journal Article

Inelastic neutron scattering was used to measure the phonon densities of states of the A15 compounds V3Si, V3Ge, and V3Co at temperatures from 10 to 1,273 K. It was found that phonons in V3Si and V3Ge, which are superconducting at low temperatures, exhibit an anomalous stiffening with increasing temperature, whereas phonons in V3Co have a normal softening behavior. First-principles calculations show that this anomalous increase in phonon frequencies at high temperatures originates with an adiabatic electron-phonon coupling mechanism. The anomaly is caused by the thermally induced broadening of sharp peaks in the electronic density of states of V3Si and V3Ge, which tends to decrease the electronic density at the Fermi level. These results show that the adiabatic electron-phonon coupling can influence the phonon thermodynamics at temperatures exceeding 1,000 K.

Full Text

Duke Authors

Cited Authors

  • Delaire, O; Lucas, MS; Muñoz, JA; Kresch, M; Fultz, B

Published Date

  • September 5, 2008

Published In

Volume / Issue

  • 101 / 10

Start / End Page

  • 105504 -

PubMed ID

  • 18851226

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.101.105504

Language

  • eng