Insight into the role of atomic interaction and ionic radius in Al doped BiFeO3: Structural, electronic, and optical properties

Chemical doped multiferroic BiFeO3 has received much research interest from both fundamental and applications due to enhanced magnetism, reduced leakage current, increased piezoelectric effect and novel optical responds. Here, we report on a theoretical investigation of structural, electronic and optical properties of Al doped BiFeO3 using density functional theory. The calculated results show that doping of Al atoms with a smaller ionic radius at the A(Bi)-site resulted in a more significant change compared to the B(Fe)-site. It confirms that the smaller ionic radius and interatomic interaction are important factors contributing to the change of atomic structure. The calculated DOS reveals that Al contributes significantly to the reduction of the energy band gap where Al 3p states are occupied in the valence band and the conduction band. This study sheds light on the Al doped BiFeO3, paving the way for the development of novel materials with excellent multiferroic and solar properties.