Modified magnetization and electron transition behavior in Bi 2 Fe 4 O 9 , Bi 2 Fe 4 O 9 -CoFe 2 O 4 and Bi 2 Fe 4 O 9 -NiFe 2 O 4
Modified magnetization and electron transition behavior in Bi 2 Fe 4 O 9 , Bi 2 Fe 4 O 9 -CoFe 2 O 4 and Bi 2 Fe 4 O 9 -NiFe 2 O 4
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DOI：
10.1016/j.ceramint.2017.10.231
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发表时间：
2018-02
影响因子：
5.2
通讯作者：
Tiantian Wang;H. Deng;Liangqing Zhu;P. Yang;J. Chu
中科院分区：
文献类型：
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作者：
Tiantian Wang;H. Deng;Liangqing Zhu;P. Yang;J. Chu
采用固相反应法合成了莫来石Bi 2Fe 4 O 9（BFO）及其与尖晶石CoFe 2 O 4（CFO）和NiFe 2 O 4（NFO）的复合材料，在室温下表现出可见光响应和增强的铁磁有序性。通过XRD、拉曼光谱和SEM图像分析，发现了复合材料中存在独立相。通过XRD图谱计算发现，尖晶石磁性含量不仅影响BFO的晶格参数和晶粒尺寸，而且影响BFO的生长择优取向。光谱分析表明BFO及其复合材料存在三个吸收边，表明BFO及其复合材料存在多个电子跃迁。BFO、BFO-NFO和BFO-CFO的带间电子跃迁分别发生在1.56、0.92和0.47 eV处。此外，M-H磁滞回线表明，由于磁性尖晶石CFO和NFO相的复合样品的铁磁性增强。不同的曲线形状和剩余磁化强度意味着CFO和NFO不同的内禀磁性。
Mullite Bi2Fe4O9(BFO) and its composites with spinel CoFe2O4(CFO) and NiFe2O4(NFO) have been synthesized by solid-state reaction, exhibiting visible-light response and enhanced ferromagnetic order simultaneously at room-temperature. Independent phases have been detected in composite samples by XRD, Raman spectroscopy and further confirmed by SEM images. Calculated through XRD patterns, it can be found that not only the lattice parameters and crystallite size, but also the growth preference orientation of BFO could be effected by spinel magnetic content. Optical spectroscopy shows three absorption edges existed which indicates multiple electron transitions for BFO and its composites. Interband electron transition occurs at 1.56, 0.92 and 0.47 eV for BFO, BFO-NFO and BFO-CFO respectively. Furthermore,M-Hhysteresis loops suggest enhanced ferromagnetism in composite samples due to magnetic spinel CFO and NFO phase. Different curve shape and remnant magnetization imply the different intrinsic magnetic nature of CFO and NFO.