Structural evolution and enhanced magnetization of Bi1−xPrxFeO3

• A full understanding of the relations among the structure, ferroelectricity, and ferromagnetization is given for Pr-doped BiFeO3 system.
• The evidence is provided for the existence of an antiferroelectric orthorhombic Pbam phase between ferroelectric orhombohedral R3c and paraelectric orthorhombic Pnma phases.
• The giant magnetization improvement is found at the boundaries of the polar–antipolar–nonpolar phase transitions.

The structural, ferroelectric, vibrational, and magnetic properties of polycrystalline Bi1−xPrxFeO3 (0≤x≤0.50) powders are investigated by the measurements of X-ray diffraction, X-ray photoelectron spectroscopy, Raman scattering spectroscopy, and magnetization at room temperature. Our results reveal that the rare-earth ion Pr substitution at Bi site causes the structural transformations from rhombohedral R3c phase to orthorhombic Pbam phase at x≈0.15, and then to orthorhombic Pnma phase at higher Pr concentration x≈0.25, accompanying the ferroelectric–antiferroelectric–paraelectric phase transition. Measurements of magnetic properties confirm that Pr substitution can improve the magnetization of BiFeO3 before approaching the first phase transition. We find that an inverse behavior occurs after passing a maximum across the antiferroelectric–paraelectric phase boundary. We also obtain the unique switching behavior in low magnetic field of Bi0.5Pr0.5FeO3 from the field dependence on magnetization, indicating the existence of the antiferromagnetic ordering.