Thermoelectric power and electronic structure of dilute alloys of nickel and cobalt with d transition elements

Abstract

We present new measurements of thermoelectric power for nickel and cobalt dilute alloys with d transition elements in two temperature ranges: from 1.3 to 4.2 K and from 77 to 300 K. We analyse the measurements at room temperature in a two-band conduction model and deduce the thermopowers associated with the matrix (Smσ) and with the impurities (Soσ) in each sub-band σ. The results obtained for the impurity thermoelectric power confirm the model of electronic structure suggested for this alloy from magnetization and resistivity measurements; this model is characterized by the occurrence of a virtual bound state supward arrowdupward arrow at the Fermi level when the charge difference between the matrix and the impurity is large enough. From the values of impurity thermoelectric power in the supward arrow sub-band, we deduce the position and the width of the virtual bound state.