Thermoelectric Properties of n-Mg2Si0.8Sn0.2 Solid Solutions with Addition of SiO2 and TiO2 Nanoinclusions

Abstract

The results of theoretical calculations show the possibility of increasing the thermoelectric figure of merit in solid solutions of Mg2Si–Mg2Sn using nanoinclusions (NEAT approach). The thermoelectric properties of the Mg2Si0.2Sn0.8 solid solution, doped with antimony to obtain the optimal concentration of free electrons, with the addition of SiO2 and TiO2 impurities as additional scattering centers were studied. During the preparation of solid solution samples by hot pressing, nanoparticles of silicon dioxide and titanium dioxide of 15–200 nm in size at a concentration of 0.5–1 vol % were added. The coefficients of thermopower, electrical conductivity, and thermal conductivity were measured on these samples in the temperature range from 300 to 800 K. An insignificant decrease in thermal conductivity was shown for samples containing additional impurities. In this case, an increase in the thermoelectric figure of merit was not observed due to a decrease in the mobility of majority carriers.