Influence of rare-earth elements doping on structure and optical properties of BiFeO3 thin films fabricated by pulsed laser deposition

Scanning electron microscopy exhibits that the number of island-like structures decreases with increasing Eu dopant. The position of the A1-1 mode of the films in the Raman spectra shifts to higher wavenumber with increasing x. With increasing the amount of Eu, the refractive index increases and the extinction coefficient decreases. In addition, the band gap of BEFOx films decreases with increasing Eu dopant.