Magnetization, Magnetoelectric Effect, and Structure Transition in BiFeO3 and (Bi0.95La0.05)FeO3 Multiferroic Ceramics

作者：Ding Y^*; Wang T H; Yang W C; Lin T C; Tu C S; Yao Y D; Wu K T

来源：IEEE Transactions on Magnetics, 2011, 47(3): 513-516.

DOI：10.1109/TMAG.2010.2103553

• (Bi0.95La0.05)FeO3
• BiFeO3
• dielectric permittivity
• grain size
• magnetization
• X-ray diffraction

Magnetization, grain size, x-ray diffraction, and dielectric permittivity of BiFeO3 (BFO) and 5 mol% lanthanum-substitution BFO [(Bi0.95La0.05)FeO3] ceramics have been carried out as a function of sintering temperature (910-950 degrees C) BFO ceramic exhibits an antiferromagnetic behavior, whose magnetization curve is linear with the field at room temperature. A weak ferromagnetic behavior occurs in (Bi0.95La0.05)FeO3 (BLFO) ceramics at room temperature, in which remanent magnetization increases from 0.008 to 0.14 as sintering temperature raises from 910 to 950 degrees C. This phenomenon can be correlated with the growth of grain size of BLFO ceramics, which grows with increasing sintering temperature. The dielectric permittivities of BFO and BLFO are about 33 and 57 at room temperature, respectively. The dielectric losses (tan delta) of BFO and BLFO ceramics vary respectively in the ranges of similar to 0.2-0.4 and similar to 0.002-0.004 below 150 degrees C, indicating that 5 mol% La-substitution can efficiently reduce electric conductivity. A frequency-dependent and broad dielectric maximum was observed in both BFO and BLFO ceramics upon heating. This dielectric response is likely triggered by the antiferromagnetic-paramagnetic transition near the Neel temperature.

• 出版日期2011-3