Size effect on magnetic and ferroelectric properties in Bi2Fe4O9 multiferroic ceramics
Size effect on magnetic and ferroelectric properties in Bi2Fe4O9 multiferroic ceramics
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DOI：
10.1063/1.3259392
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发表时间：
2009-11
影响因子：
3.2
通讯作者：
Z. Tian;S. Yuan;Xueli Wang;X. F. Zheng;S. Yin;C. Wang;L. Liu
中科院分区：
文献类型：
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作者：
Z. Tian;S. Yuan;Xueli Wang;X. F. Zheng;S. Yin;C. Wang;L. Liu
采用改进的Pechini法制备了不同晶粒尺寸（60 ~ 2000 nm）的Bi2Fe4O9多晶陶瓷，研究了其磁性和铁电性能。结果表明，磁性和铁电性能与晶粒尺寸密切相关。对于60 nm样品，磁化曲线表现出反铁磁（AFM）和铁磁（FM）分量的叠加行为。随着晶粒尺寸的增大，FM分量被抑制，AFM相互作用占主导地位。同时，随着晶粒尺寸的增大，Neel温度（TN）向高温转变。与60 nm样品相比，由于泄漏电流的减小，大晶粒尺寸样品（> ~ 200 nm）在室温下观察到铁电磁滞回。在所有样品中，900 nm样品的漏电流密度最小（<10−6），残余极化最大（0.21 μC/cm2）。
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 (TN) 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 μC/cm2).