Theoretical study of electronic, thermoelectric and optical properties of quaternary Heusler alloys FeRuTiSi and FeRuTiGe

Abstract

In this study, we investigated the electronic, thermoelectric, and optical properties of nonmagnetic semiconductors Heusler FeRuTiSi and FeRuTiGe. Our results show that FeRuTiSi has a band gap of 0.34eV, while FeRuTiGe has a slightly smaller band gap of 0.14eV. The calculated Seebeck coefficient at room temperature is −634μV/K for FeRuTiSi and −281μV/K for FeRuTiGe, indicating that FeRuTiSi is a better thermoelectric material with a higher figure of merit of 0.84 at 300K compared to FeRuTiGe’s figure of merit of 0.76 at the same temperature. Moreover, the optical properties of both Heusler alloys exhibit similar behaviors, with a reflectivity of approximately 55% in the visible spectrum and reaching a maximum of 60% in the ultraviolet region.