Origin of high room temperature ferromagnetic moment of nanocrystalline multiferroic BiFeO3
Origin of high room temperature ferromagnetic moment of nanocrystalline multiferroic BiFeO3
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DOI：
10.1063/1.3132586
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发表时间：
2009-05
影响因子：
4
通讯作者：
S. Vijayanand;H. S. Potdar;P. Joy
中科院分区：
文献类型：
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作者：
S. Vijayanand;H. S. Potdar;P. Joy
采用自燃烧法在室温下合成了平均晶粒尺寸为<$25 nm、具有很高磁化强度的单相纳米晶BiFeO 3。高于室温的磁性测量显示低于645 K的场冷却和零场冷却磁化之间的偏差，所述645 K是块体材料的尼尔温度（TN），指示铁磁性的固有性质。然而，观察到一个广泛的磁过渡以上TN的BiFeO 3和扩展到800 K表明Fe 3 O 4作为一个可能的磁性杂质相的存在。Fe 3 O 4存在的证据是从粉末X射线衍射图的详细分析中获得的。
Single phase nanocrystalline BiFeO3 of average crystallite size ∼25 nm with very high magnetization at room temperature is synthesized by an autocombustion method. Magnetic measurements above room temperature show deviation between field cooled and zero field cooled magnetization below 645 K, the Neel temperature (TN) of the bulk material, indicating intrinsic nature of ferromagnetism. However, observation of a broad magnetic transition above TN of BiFeO3 and extended up to 800 K suggests the presence of Fe3O4 as a possible magnetic impurity phase. Evidence for the presence of Fe3O4 is obtained from detailed analysis of the powder x-ray diffraction pattern.