Thermoelectric Properties of Ternary Rare-Earth Copper Antimonides LaCu<I><SUB>x</SUB></I>Sb<SUB>2</SUB> (0.9&le;<I>x</I>&le;1.3)

Abstract

Ternary rare-earth antimonides LaCu x Sb 2 with 0:9 x 1:3 were prepared by arc melting the constituents and annealing the obtained products at 973 K for 144 h. The annealed products were then consolidated by pressure-assisted sintering at 1043 K for 3 h. X-ray powder diffractometry showed that all the sintered samples crystallized in the tetragonal HfCuSi 2 -type structure. While the lattice constant c increased with Cu content, the lattice constant a came to minimum at x ¼ 1:0. In the temperature range 300-800 K, the Seebeck coefficients of all the samples were positive. The Seebeck coefficient and electrical resistivity were observed to increase with the temperature. The decrease in the Cu content resulted in the increase in the Seebeck coefficient and electrical resistivity, and hence improving slightly the thermoelectric power factor. However, the thermoelectric power factor was substantially smaller than that of state-of-the art thermoelectric materials.

Electron-phonon interaction in ternary rare-earth copper antimonides LaCuSb<inf>2</inf> and La(Cu<inf>0.8</inf>Ag<inf>0.2</inf>)Sb<inf>2</inf> probed by Yanson point-contact spectroscopy

“…The latter contains a rare-earth element and antimony instead of arsenic but does not contain iron [3]. This family including the superconducting systems LaNiSb2, LaCuSb2, LaPdSb2 and others was investigated thoroughly concerning their magnetic and transport properties by Muro et al [3], Myers [4], and thermoelectric properties by Ohta [5].…”