Journal of Low Temperature Physics

, Volume 9, Issue 1–2, pp 1–9 | Cite as

The Kohn anomaly in the phonon spectrum of niobium

  • V. Chopra
Article

Abstract

Accurate resistivity measurements have been carried out on Nb-W and Nb-Ti alloy systems in the normal state in the temperature range 2–9 K. A sharp drop occurs in the lattice contribution to the resistivity at a temperature (the kink temperature) which depends on the nature of the alloying impurity and its concentration. A corresponding anomalous behavior of the specific heat, where the straight-line plot ofC/T vs.T displays two slopes, has been attributed by some workers to a change in the Debye temperature of niobium at the kink of the resistance, while others believe it to be due to acoustic plasmons which dominate at low temperatures. Our resistivity data provide strong evidence in support of the former view; the Debye variation is expected to be caused by the presence of the Kohn anomaly in the lattice spectra of niobium.

Keywords

Normal State Niobium Magnetic Material Resistivity Measurement Alloy System 

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Copyright information

© Plenum Publishing Corporation 1972

Authors and Affiliations

  • V. Chopra
    • 1
  1. 1.The Clarendon LaboratoryUniversity of OxfordOxfordEngland

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