Band-gap Tuning and Magnetic Properties of Heterovalent ions (Ba, Sr and Ca) Substituted BiFeO3 Nanoparticles

A Comparative study of heterovalent Ba, Sr and Ca ions substitution on the structural, vibrational, optical and magnetic properties of BiFeO3 nanoparticles was carried out. The distorted rhombohedral structure was confirmed from both X-ray diffraction and Raman spectroscopy techniques in pure BiFeO3 and Bi(0.85)A(0.15)FeO(3) ( A=Ba, Sr and Ca) samples. UV-Visible spectroscopy results show that the band-gap of BiFeO3 nanoparticles can be tuned by heterovalent ions substitution from 2.12 eV for BiFeO3 to 2.10, 2.06 and 2.03 eV for Ca, Sr and Ba substituted BiFeO3 nanoparticles respectively. The magnetic measurements indicate enhancement in magnetization for heterovalent A(2+) substituted BiFeO3 samples and the magnetization increases with increase of ionic radius of the substituted ions.