Bi/Sb distribution and its consequences in solid solution members of the thermoelectric materials K 2Bi 8− xSb xSe 13

Abstract

In an effort to understand the nature of mass fluctuations introduced when β-K 2Bi 8Se 13 is alloyed with K 2Sb 8Se 13 we determined the detailed crystal structures of two solid solutions of the type K 2Bi 8− x Sb x Se 13 with x=4.0 and x=2.4. The structure is that of β-K 2Bi 8Se 13 which is a promising thermoelectric material with low thermal conductivity. The single crystal structures of K 1.49Bi 4.72Sb 3.79Se 13 and K 1.49Bi 5.55Sb 2.97Se 13 were determined and the Bi/Sb distribution in the structures was examined.