Phonon drag induced by Einstein mode in ZrB₁₂

Abstract

Abstract We report on the first measurements of the Seebeck effect for single crystals of superconductor ZrB 12 ( T c ≈ 6.1 K) at temperatures 2.5–300 K in magnetic fields H 0 < 1 kOe. The experimental data evidently prove that the Seebeck coefficient S ( T ) at T > 20 K is controlled by the electron coupling to a soft phonon Einstein mode having the characteristic energy Θ E = ħω E / k B ≈ 216 K. The origin of the S ( T ) anomalies detected in the temperature interval T < 11 K is discussed in terms of the electron DOS renormalization and the superconductivity in ZrB 12 . (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)