Correlation between transport properties and quasielastic linewidths of Ce and Yb compounds with unstable 4f-shell

Abstract

From an analysis of available data it is shown that there is experimental evidence for a rather general correlation of electrical resistivity, ϱ, and thermopower with the quasielastic linewidth of the neutron spectra, Γ QE, for intermetallic Ce- and Yb-compounds with an unstable 4f-shell. At high temperatures, k B T > Γ QE, the 4f-contribution to the resistivity, Δϱ, scales with Γ −1 QE. For Ce-compounds, which show a resistivity maximum, the measured strong temperature dependence of Γ QE corresponds to the temperature dependence of the resistivity above the resistivity maximum over a few hundred K. Empirical expressions for resistivity and thermopower are presented, which not only yield the observed correlation for k B T > Γ QE, but which also describe the low temperature decrease of the two quantities: Fits for the resistivities and the thermopowers of a large number of Ce- and Yb-compounds are is very good agreement with the data over a large range of temperatures. The correlation as well as the empirical expressions for resistivity and thermopower are discussed within a model of M. Weger, which has recently been proposed to account for the so called “resistivity saturation” observed in materials with narrow bands.