Low temperature transport properties of the BiCuSeO system

The discovery of a 26 K superconductivity in the tetragonal iron-based pnictide LaFeAsO1-xFx (x = 0.05-0.12) has stimulated a tremendous search for superconductivity in a wide class of materials with similar structure. Beside superconductivity, promising thermoelectric properties have been discovered in this family in the cryogenic temperature range and in the p-type BiCuSeO system around 400-600 C. In this paper, we report on the effect of various substitutions on the low temperature properties of this system. Whatever the substitution, all samples revealed p-type, and no superconductivity was observed. Moreover, although some of these compounds exhibit very promising thermoelectric properties above room temperature, this is not the case in the low temperature range. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)