Thermoelectric properties of URu2Si2 and U2Ru3Si5

The new possibility of uranium noble metal silicides for thermoelectric materials was investigated by the analogy with transition-metal silicides having good thermoelectric power. The Seebeck coefficient and electrical resistivity of URu 2 Si 2 and U 2 Ru 3 Si 5 were measured in the temperature range from 300 to 1100 K and Hall coefficient at room temperature. The Seebeck coefficients of URu 2 Si 2 and U 2 Ru 3 Si 5 were obtained to be -48.9 and -32.8 μV K -1 at 1100 K, respectively. The temperature dependences of the electrical resistivities for URu 2 Si 2 and U 2 Ru 3 Si 5 were small, which are similar to that of uranium metal rather than that of silicon semiconductor. As thermoelectric materials for high temperatures, URu 2 Si 2 and U 2 Ru 3 Si 5 were thought to be not promising.