Size effect on magnetic and ferroelectric properties in Bi2Fe4O9 multiferroic ceramics

作者：Tian Z M; Yuan S L^*; Wang X L; Zheng X F; Yin S Y; Wang C H; Liu L

来源：Journal of Applied Physics, 2009, 106(10): 103912.

DOI：10.1063/1.3259392

Magnetic and ferroelectric properties are investigated for the polycrystalline Bi2Fe4O9 ceramics with different grain sizes (60-2000 nm) synthesized by a modified Pechini method. It shows that magnetic and ferroelectric properties are strongly dependent on the grain size. For the 60 nm samples, the magnetization curves exhibit a superimposed behavior of antiferromagnetic (AFM) with ferromagnetic (FM) component. As the grain size increases, FM component is suppressed and AFM interaction becomes dominant. Simultaneously, the Neel temperature (T-N) shifts to high temperatures as the grain size increases. Compared with the 60 nm sample, ferroelectric hysteresis loops at room temperature are observed for the samples with large grain sizes (>200 nm) due to the reduced leakage currents. Among all samples, the 900 nm sample is found to have the smallest leakage current density (<10(-6)) and the largest remnant polarization (0.21 mu C/cm(2)).

• 出版日期2009-11-15
• 单位华中科技大学