Role of charge states and dopant site in governing electronic properties of Cr doped BiFeO3

In this work, the influence of incorporation of Cr in multiferroic BiFeO3 (BFO) using first principle calculations based on GGA + U approximation is investigated. The substitution of Cr is studied at Bi, Fe and O lattice sites and interstitial position in BiFeO3. The stability of the defects is studied via formation energy calculations for different charge states of various Cr related defects in BFO at realistic conditions (T, pO(2)). From the analysis of the formation energy calculations derived for the different configurations, Cr is found to preferentially occupy the Fe site in BFO. Oxygen and bismuth vacancies play an important role in the conduction mechanisms. The migration energetics are studied for these vacancies in pure and doped BFO and the changes that occur in migration barriers upon Cr substitution are discussed.

Automated summary

This study investigates the influence of incorporating Cr into multiferroic BiFeO3 using first principle calculations, finding that Cr prefers to occupy the Fe site. Oxygen and bismuth vacancies play significant roles in conduction mechanisms in BFO, and the migration energetics for vacancies are studied in both pure and doped BFO, with discussion on changes in migration barriers upon Cr substitution.