Thermoelectric Properties of Mo and Ge co-substituted CrSi2

Abstract

The thermoelectric properties of Mo and Ge co-substituted CrSi 2 have been investigated. Polycrystalline samples of (Cr 1− x Mo x )Si 2 ( x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) and (Cr 0.92 Mo 0.08 )(Si 1− y Ge y ) 2 ( y = 0, 0.01, and 0.02) were prepared by the two-step arc-melting method followed by spark plasma sintering and annealing. Powder X-ray diffraction confirmed that single-phase (Cr 1− x Mo x )(Si 1− y Ge y ) 2 samples were obtained. Mo and Ge co-substitution in CrSi 2 resulted in both an increase in the power factor and a large decrease in the thermal conductivity, which resulted in a high figure-of-merit ( zT ) value for the (Cr 0.92 Mo 0.08 )(Si 0.99 Ge 0.01 ) 2 sample ( zT = 0.29 at 700 K). This zT value is the highest reported value for CrSi 2 -based thermoelectric materials.