Thermoelectric power study of Eu1-xLaxB6 (x=0.0, 0.1, 0.2)

Abstract

Temperature-dependent thermoelectric power (TEP) was measured in the range of 2 K < T < 300 K for single crystals of Eu1-xLaxB6 (x = 0.0, 0.1, and 0.2). For Eu1-xLaxB6 (x = 0.0 and 0.1), the TEP shows negative values in the whole temperature range, consistent with the fact that dominant charge carriers in Fermi surface are electrons. However, for Eu1-xLaxB6 (x = 0.2), a sign change of the TEP from negative to positive value is observed at about 28 K, which is consistent with the sign reversal of Hall resistivity of the same compound. We surmise that the anomalous sign reversal seems to be accompanied by a magnetic transition from ferromagnetic to anti ferromagnetic with La doping in Eu1-xLaxB6. (c) 2006 Elsevier B.V. All rights reserved.