Structural, electronic, vibrational, thermoelectric and mechanical properties of Li based quaternary Heusler compound LiTiCoSn: A DFT approach

Abstract

Thermoelectrics are a unique hope to rise above the energy crisis due to their pollution-free nature of energy generation. As per such green opportunities, here the thermoelectric behavior, as well as the structural, electronic properties and vibrational properties of the newly discovered Li-based quaternary Heusler compound i.e.LiTiCoSn, are investigated. The mechanical and elastic properties are also calculated for the practical utilization of the material i.e. for the formation of Thermoelectric Modules (TEM). This study is carried out in the theoretical research frame of first principle calculations as well as the Boltzmann transport equations. All the thermoelectric properties are calculated at the three different temperatures for the chemical potential. The compound is found dynamically stable with the cubic (FCC) crystal structure, showing p-type semiconducting behavior with the indirect bandgap of 0.85 eV. The highest thermoelectric performance (ZT) at the 1600 K temperature is 0.43. The compound has suitable mechanical properties and possesses a minimum resistance against Shear deformations with a ductile nature. The calculated melting point of the material is 2190 ± 300 K allows it to become an efficient material in the higher temperature regions due to which all the thermoelectric properties are discussed in the temperature range of 100 K to 1600 K. Here the compound is first time described in the detailed prospectus; hence can light the path of experimental and future research.