Nernst effect of the intermediate valence compound YbAl3: revisiting the thermoelectric properties. (23rd February 2015) - Wei, Beipei
Abstract: The Nernst effect and thermopower of the prototypical Yb-based intermediate valence compound YbAl3 were investigated. Different to the thermopower whose absolute values are enhanced with increasing temperature and assume a broad maximum at 175 K, the Nernst coefficient of YbAl3 is enhanced only below T ≈ 75 K. While the two quantities in the heavy-fermion compound CeCu2 Si2 were recently found to be related by the anomalous Hall mobility due to the local asymmetric Kondo scattering, this theorem fails when being applied to YbAl3 . Rather, the thermopower of YbAl3 is well described by a simple narrow-band model. We discuss the reason for this in terms of the intermediate valence nature of YbAl3 that is conceptually different from the local Kondo physics.