Structural, electrical and magnetic properties of Bi0.825Pb0.175FeO3, and Bi0.725La0.1Pb0.175FeO3 multiferroics

Single-phase BiFeO3, Bi0.825Pb0.175FeO3 and Bi0.725La0.1Pb0.175FeO3 ceramic samples were prepared via solid state reaction route to study the effects of co-doping (La/Pb) on their crystal structure and ferroelectromagnetic behaviour. X-ray diffraction data accompanied by Rietveld refinement showed that BiFeO3 crystallize in rhombohedral distorted perovskite structure (space group-R3c) while to that BPFO and BLPFO crystallize in tetragonal (P4/mmm) symmetry. Presence of E(TO9) and E(LO9) modes in Raman scattering spectra for BiFeO3 and Bi0.725La0.1Pb0.175FeO3 infers ferroelectric nature. However, absence of both modes in Bi0.875Pb0.175FeO3 indicates the paraelectric nature. The room temperature dielectric constant (10 Hz–1 MHz) of BiFeO3, Bi0.825Pb0.175FeO3 and Bi0.725La0.1Pb0.175FeO3 is about 100, 60, and 200. Ferroelectromagnetic measurements revealed the existence of ferroelectricity with remnant polarization of 0.24 μC/cm2 in Bi0.725La0.1Pb0.175FeO3, paraelectricity in Bi0.875Pb0.175FeO3, and weak (strong) ferromagnetism with remnant magnetizations of 0.25 (1.57) emu/g in Bi0.725La0.1Pb0.175FeO3 (Bi0.825Pb0.175FeO3).