Effect of alloying at different lattice sites on the electronic structure regulation of BaTiO3 and evaluation of its alloying feasibility

Abstract

Perovskite-structured oxides show substantial application potential in optoelectronic, ferroelectric devices and catalysis, benefiting from their excellent chemical stability, unique electronic structure and optical properties. As a representative perovskite oxide, BaTiO₃ serves as a core functional material in the electronics industry due to its superior dielectric, ferroelectric and optoelectronic performances. However, the variation rules of its electronic structure induced by element alloying at different lattice sites (Ba, Ti, O) and the feasibility of such alloying remain insufficiently understood. Herein, first-principles calculations were employed to systematically investigate the electronic structure variations and alloying difficulty of BaTiO₃ with Sr (Ba-site), Zr (Ti-site) and S (O-site) doping at different concentrations. Results indicate that Sr and Zr alloying cause a gradual band gap widening with increasing doping concentration, whereas S alloying leads to band gap narrowing. Mixing enthalpy calculations reveal that Sr alloying is more feasible than Zr and S alloying, which is further clarified from the electronic structure perspective. This work provides a crucial theoretical basis for BaTiO₃ alloying research.