MAGNETIC AND THERMOELECTRIC PROPERTIES OF R3CU3SB4 (R=LA, CE, GD, ER)

The rare-earth compounds R3Cu3Sb4 (R = La, Ce, Gd, Er) were synthesize d in order to evaluate their potential for thermoelectric applications . Melting in closed tantalum tubes was used to get the materials witho ut loss of volatile Sb components. The structure and the thermal expan sion coefficients of these compounds were determined by temperature-de pendent x-ray diffraction measurements. We also determined the effecti ve magnetic moments of the rare-earth ions and their valence state. Th e resistivity of the compounds was measured over a large temperature r ange from 2 to 470 K. Hall-effect measurements were performed in the r ange from 30 to 470 K. Additionally, the thermopower and the thermal c onductivity were determined. On the basis of the measured data, an est imation of the thermoelectric potential of this group of materials wil l be given. (C) 1998 American Institute of Physics.