Magnetic and thermoelectric properties of R3Cu3Sb4 (R=La, Ce, Gd, Er)

Abstract

The rare-earth compounds R3Cu3Sb4 (R=La, Ce, Gd, Er) were synthesized in order to evaluate their potential for thermoelectric applications. Melting in closed tantalum tubes was used to get the materials without loss of volatile Sb components. The structure and the thermal expansion coefficients of these compounds were determined by temperature-dependent x-ray diffraction measurements. We also determined the effective magnetic moments of the rare-earth ions and their valence state. The resistivity of the compounds was measured over a large temperature range from 2 to 470 K. Hall-effect measurements were performed in the range from 30 to 470 K. Additionally, the thermopower and the thermal conductivity were determined. On the basis of the measured data, an estimation of the thermoelectric potential of this group of materials will be given.