Highly effective Mg2Si1-xSnx thermoelectrics

Results of detailed investigations of Mg2BIV (B-IV=Si, Ge, Sn) compounds and their quasibinary alloys are presented. Our analysis revealed that Mg2Si-Mg2Sn system has the most promising for thermoelectric applications combination of transport properties and band structure features. The n-type Mg2Si1-xSnx solid solutions were studied in broad range of compositions and electron concentration (up to 5x10(20) cm(-3)). Temperature dependencies of figure of merit were determined in temperature range 300-870 K using results of simultaneous measurements of Seebeck coefficient, electrical, and thermal conductivities. The alloy of optimized composition has reproducible figure of merit ZT(max)=1.1. The results of the present study are compared with the data for best modern thermoelectrics.