Tailoring the Magnetic and Optical Characteristics of Nanocrystalline BiFeO3 by Ce Doping.

The Ce-doped BiFeO3 ( BFO) nanoparticles ( NPs) were synthesized using a facile sol-gel route with varying Ce concentrations in the range of 1-5 mol%. Ferroelectric transition temperature was found to shift from 723°C ± 5°C for pristine BFO NPs to 534°C ± 3°C for 5 mol% Ce-doped BFO NPs. UV- Vis absorption spectra of BFO NPs showed a significant blue shift of ~100 nm on Ce doping. The Fourier transformed infrared ( FTIR) spectrum centered ~ 550 cm−1 becomes considerably broadened on Ce doping which is due to additional closely spaced vibrational peaks as revealed by the second derivative FTIR analysis. High-frequency EPR measurements indicated that clustering occurs at high dopant levels, and that Fe is present as Fe3+, corroborating Mössbauer measurements. The values of saturation and remanent magnetization for 3% Ce-doped BFO NPs are 3.03 and 0.49 emu/g, respectively, which are quite significant at room temperature, making it more suitable for technological applications. [ABSTRACT FROM AUTHOR]