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

• Published in: Solid state communications Vol. 368; p. 115191
• Main Authors: Mouchou, S., Toual, Y., Azouaoui, A., Bouslykhane, K., Benzakour, N., Hourmatallah, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023
• Subjects: Optical properties; Quaternary Heusler; Superluminal; Thermoelectric material; Quaternary Heusler; Thermoelectric material; Optical properties; Superluminal
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2023.115191

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. •FeRuTiSi and FeRuTiGe are nonmagnetic semiconductors with indirect bandgaps.•Both Heuslers exhibit a flat band in the Γ-X direction.•FeRuTiSi has very low thermal and electrical conductivities below 300 K.•FeRuTiSi has a large Seebeck coefficient (S = -634 μV/K) and zT = 0.84.•Both alloys show reflectivity over 40% and good optical absorption.