The magnetoelectric coupling in rhombohedral–tetragonal phases coexisted Bi0.84Ba0.20FeO3

Abstract Ba doped Bi 1.04− x Ba x FeO 3 ceramics with x up to 0.30 have been prepared by the tartaric acid modified sol–gel method. The X ray diffraction patterns show that the structure transforms from rhombohedral to tetragonal with increasing the Ba substitution concentration from 10% to 30% and the coexistence of distorted rhombohedral and tetragonal phases in 20% Ba substituted BiFeO 3 , which was further confirmed by the Raman spectra. Bi 0.84 Ba 0.20 FeO 3 exhibits the highest magnetization (1.6 emu/g under magnetic field of 12 kOe) compared with the other samples of different Ba substitution concentration. Significant enhancement of the ferroelectricity has been observed in 20% and 30% Ba substituted BiFeO 3 with saturate polarization close to 6.6 μC/cm 2 for Bi 0.74 Ba 0.30 FeO 3 . The magnetoelectric coupling of Bi 0.84 Ba 0.20 FeO 3 has been measured and the maximum decrease of magnetization under magnetic field of 9.8 kOe was about 0.06 emu/g with increasing applied electric field to 11 kV/cm, and the magnetoelectric coefficient is 1.5×10 −12  s/m.