Influence of the La 3+ , Eu 3+ , and Er 3+ Doping on Structural, Optical, and Electrical Properties of BiFeO 3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method

In this study, nanocrystalline (18–28 nm) perovskite-like bismuth ferrite rare earth-doped powders (Bi 0.9 RE 0.1 FeO 3 , where RE = La (BLaFO), Eu (BEuFO), and Er (BErFO)) were obtained by microwave-assisted modification of solution combustion synthesis (SCS). The influence of high load La 3+ , Eu 3+ , and Er 3+ doping on structural, optical, and electrical properties of BiFeO 3 was investigated. It was found that rare earth doping along with fast phase formation and quenching significantly distorts the crystal cells of the obtained materials, which results in the formation of mixed rhombohedral- (R3c-) orthorhombic (Pbnm) crystal structures with decreased lengths of Bi-O and Fe-O bonds along with a decreasing radius size of doping ions. This promotes reduction of the optical band gap energy and suppression of ionic polarization at high frequencies and results in enhanced dielectric permittivity of the materials at 1 MHz.