Magnetoelectric coupling and phase transition in BiFeO3 and (BiFeO3)(0.95)(BaTiO3)(0.05) ceramics

作者：Wang T H; Tu C S^*; Chen H Y; Ding Y; Lin T C; Yao Y D; Schmidt V H; Wu K T

来源：Journal of Applied Physics, 2011, 109(4): 044101.

DOI：10.1063/1.3551578

In situ high-resolution synchrotron x-ray diffraction reveals a local minimum in rhombohedral distortion angle alpha(R) (associated with an inflection in the lattice constant a(R)) near 400 and 350 degrees C in BiFeO3 (BFO) and (BiFeO3)(0.95)(BaTiO3)(0.05) (BFO-5%BT), respectively. It suggests a coupling between ferroelectric and magnetic parameters near the antiferromagnetic-paramagnetic transition, which is responsible for the broad frequency-dependent dielectric maxima. A rhombohedral (R)-orthorhombic (O)-cubic (C) transition sequence takes place near 820 and 850 degrees C in BFO upon heating. BFO-5%BT exhibits a R-C transition near 830 degrees C. The BaTiO3 substitution can enhance dielectric and ferromagnetic responses and reduce electric leakage. The dielectric loss of BFO-5%BT remains less than 0.04 below 150 degrees C.

• 出版日期2011-2-15