First-principles study on the electronic band profiles, structural, mechanical and thermoelectric properties of semiconducting MgSc2Te4 and MgY2Te4 Spinels

New materials for renewable energy applications (e.g., thermogenerators, solar cells, etc.) are crucial to explore. Spinel's compounds have attracted great attention in recent years for their direct energy band gaps and high transition rates. Therefore, in the present research work, the structural parameters, elastic, and thermoelectric properties of magnesium-based spinel compounds MgB2Te4 (B = Sc, Y) have been investigated using density functional and Boltzmann transport theory. The elastic properties of these spinels are also explored for the first time. These compounds are elastically stable and brittle in characters. The mBJ + SOC band structure calculation shows that MgSc2Te4 and MgY2Te4 have semiconducting natures with a direct band gap. The calculated band gap values are 0.87 eV and 1.17 eV for MgSc2Te4 and MgY2Te4, respectively. Based on the Bader strategy, a deep analysis was conducted, showing that a global mixed ionic/covalent bonding appears in all studied materials that leads to drastic changes in their intrinsic properties. To characterize the thermoelectric behavior of these compounds, the BoltzTrap code is employed to evaluate the variations in the essential transport properties as a function of temperature and chemical potential. The obtained results highlight the significance of these two spinels for optical and thermoelectric applications. In the absence of experimental results, this work can be useful for future investigations.

Automated summary

This research investigates the structural, elastic, and thermoelectric properties of magnesium-based spinel compounds MgB2Te4 (B = Sc, Y) using density functional and Boltzmann transport theory. The findings reveal that these compounds are elastically stable and brittle, with direct band gaps. The study also highlights the presence of mixed ionic/covalent bonding and the potential applications of these spinels in optical and thermoelectric fields.