Thermoelectric properties of yttrium-doped Mg3(Sb,Bi)2 synthesized by melting method

Abstract

A thermoelectric compound of n-type Mg3Sb2 is a promising candidate as an element of practical thermoelectric modules. We established a low-cost synthesis-procedure for Y-doped Mg3(Sb,Bi)2 that can be easily scaled up for mass production. Samples of Mg3+δYxSb1.5Bi0.5 were synthesized via a melting method using a stainless-steel container for sealing the melt, and their thermoelectric properties depending on the Mg and Y concentrations were characterized. The highest dimensionless figure-of-merit (ZT) was obtained with the Mg3.3Y0.02Sb1.5Bi0.5 sample, which exhibited a value of ZT = 1.16 at T = 759 K.