Effect of Elemental Doping on the Electrical and Thermal Properties of Porous BiFeO3

Perovskite BiFeO 3 is a multifunctional oxide material with advantages such as low cost, high thermal stability, and low-thermal conductivity. Currently, research on BiFeO 3 mainly focuses on its multiferroic and optoelectronic properties, whereas studies on its electrical and thermal properties are relatively rare. Herein, first-principles calculations are employed to investigate the formation energies of 18 different dopants substituted at Bi sites in BiFeO 3 , including the isovalent anion Sb as well as cations with varying valence states. Bulk samples of pure porous BiFeO 3 and doped systems are prepared by solid-state sintering, and electrical and thermal properties are characterized. Pure BiFeO 3 exhibited a low electrical conductivity of 7.78 Sm −1 at 300 °C. Doping BiFeO 3 with Yb effectively tunes its porosity, which in turn modulates its electrical conductivity. The Yb-doped sample exhibits an electrical conductivity of 10.37 Sm −1 at 300 °C, representing an ≈33.3% increase compared to that of undoped BiFeO 3 . Although the thermal conductivity slightly rises from 0.96 to 1.26 Wm −1 K −1 at 300 °C, it remains relatively low compared to values reported in previous studies. This study provides new insights into the exploration of the electrical and thermal properties of BiFeO 3 materials.