Multiferroic properties of (Bi1-xPrx)(Fe0.95Mn0.05)O3 thin films

The effects of Pr substitution on the structures, magnetism and electrical properties of Bi(Fe0.95Mn0.05)O-3 films are investigated systematically. X-ray diffraction and Raman spectra results confirm that a phase transition from rhombohedral to tetragonal structure occurs at about 15% Pr substitution. The X-ray photoelectron spectroscopy reveals that Fe2+ in the films can be suppressed by Pr substitution. Enhanced ferromagnetism at room temperature is observed near the phase boundary composition. The increased remanent magnetization in the 15% Pr-substituted film can be understood by taking into account both the modification of the short-range canted G-type antiferromagnetic order at phase boundaries and the suppression of long-range incommensurate spin cycloid of BiFeO3 due to Pr substitution. Meanwhile, large ferroelectric remanent polarization of un-doped BFO can be maintained when Pr concentration is less than 20%. With 15% Pr substitution, the film shows a large remanent polarization of 62 mu C/cm(2) and a reduced coercive field of 217 kV/cm. These results demonstrate that doped BFO films with compositions near phase boundary may be promising candidates for multifunctional applications due to the simultaneous exhibition of enhanced ferromagnetism and superior ferroelectric properties. (C) 2011 Elsevier B.V. All rights reserved.