An accurate DFT insights into optoelectronic, magnetic, thermodynamic and thermoelectric characteristics of monoclinic spiroffite CoTeO

This study examines the physical characteristics of CoTeO in the spiroffite structure using an ab initio approach. The optimization of the CoTeO structure, in both nonmagnetic and magnetic states, indicates that the magnetic state is more stable than the non-magnetic one. Thermodynamic properties under various temperatures and pressures, calculated via the quasi-harmonic approximation, reveal that the specific heat capacity of spiroffite CoTeO conforms to the Debye model and satisfies the Dulong and Petit limits. The electrical, magnetic, and optical properties of CoTeO are investigated using the GGA and TB-mBJ approximations. Analysis of the density of states and the band structure indicates that spiroffite CoTeO exhibits semiconductor characteristics in both the spin up and spin down channels. The study is extended to apply hydrostatic pressure to assess the electronic and magnetic properties of both unstrained and strained structures of CoTeO. It is found that within the investigated pressure range (0–15 GPa), no structural changes are observed. Furthermore, a slight decrease in the spin up gap is noted, while no appreciable changes are observed in the spin down gap. Moreover, the investigation into the spin-polarized thermoelectric properties of the material reveals that it achieves a high figure of merit, approximately 0.99, across broad temperature spectra. This performance highlights its suitability as a candidate for thermoelectric power generation. Finally, optical properties calculations on spiroffite CoTeO reveal efficient absorption in the ultraviolet region.