Effect of addition of Ge on the thermoelectric properties of ReSi1.75 single crystals

Abstract

The effect of Ge addition on the thermoelectric properties of ReSi1.75 single crystals has been investigated in the temperature range between 323 and 1073 K. The value of the electrical resistivity along [100] of the ternary alloys is lower than that of the binary in the whole temperature range, while the value along [001] of the ternary approaches to the value of the binary as the temperature increases. The band-gap along [001] for the ternary alloys is smaller than that of the binary. The ternary alloys show the large values of the Seebeck coefficient along [001] at 323 K. The maximum dimensionless figures of merit of 0.45 at 923 K and 0.8 at 1073 K are obtained for ReSi1.73Ge0.02 samples along [100] and [001], respectively.