Structural, magnetic and dielectric properties of Pr-modified BiFeO3 multiferroic

The structural, vibrational, magnetic and dielectric properties of polycrystalline BiFeO3 and Bi0.95Pr0.05FeO3 are investigated by combining X-ray diffraction, Raman scattering spectra, magnetometry and dielectric measurements. Structural symmetry with rhombohedral R3c phase is revealed for both parent and 5% Pr substitution at Bi site, serving no chemical pressure and causes no structural transition from R3c to any other phase is identified from X-ray diffraction patterns and Raman scattering spectra. The shifting of phonon modes towards higher frequency side is attributed to lower atomic mass of Pr ion as compared to Bi ion. The magnetic measurements at room temperature indicate that Pr substitution induces ferromagnetism and discerns large and non-zero remnant magnetization as compare to pristine BiFeO3. Both dielectric permittivity and loss factor of Bi0.95Pr0.05FeO3 strongly decreases with increased frequency. Significant role of hopping of oxygen ion vacancies in Bi0.95Pr0.05FeO3 is inferred from modulus spectra and ac conductivity analysis. (C) 2013 Elsevier B. V. All rights reserved.