Substitution-driven enhanced magnetic and ferroelectric properties of BiFeO3 nanoparticles
Substitution-driven enhanced magnetic and ferroelectric properties of BiFeO3 nanoparticles
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DOI：
10.1016/j.jallcom.2015.10.250
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发表时间：
2016-02-15
影响因子：
6.2
通讯作者：
Kanagadurai, R.
中科院分区：
文献类型：
--
作者：
Vijayasundaram, S. V.;Suresh, G.;Kanagadurai, R.
通过改进的 Pechini 溶胶-凝胶工艺合成了多铁性 BiFeO3 (BFO) 纳米粒子以及稀土元素 Gd 和过渡金属 Co 的共取代。在 X 射线衍射分析的帮助下，确定了由于包含 Gd 和 Co 而引起的菱面体相 (R3c) 中由成分驱动的结构变化。通过场发射扫描电子显微镜研究观察到平均晶粒尺寸小于 BFO 自旋周期的致密扁圆纳米球，发现晶粒尺寸随着取代离子浓度的增加而减小。共取代改变了 BFO 的原始磁性结构，最终导致自发磁化强度的增强，从 M-H 磁滞回线可以明显看出。 ZFC 和 FC 曲线之间的巨大差异表明共取代样品中存在一定的玻璃态。除了观察到的晶体结构扭曲之外，XPS 证实 Fe2+ 离子的大量减少有利于极化的增强。 (C) 2015 Elsevier B.V. 保留所有权利。
Multiferroic BiFeO3 (BFO) nanoparticles along with co-substitution of Gd, a rare-earth element, and Co, a transition metal, were synthesized through modified Pechini sol-gel process. A compositional-driven structural change in the rhombohedral phase (R3c) due to the inclusion of Gd and Co was identified with the help of X-ray diffraction analysis. Dense oblate nanospheres with average grain sizes less than the spin periodicity of BFO were observed through field emission scanning electron microscopy studies, where the grain sizes were found to decrease with increasing concentration of substituent ions. The co-substitution modified the BFO's original magnetic structure, which eventually led to the enhancement of spontaneous magnetization as evident from their M - H hysteresis loops. Large difference between ZFC and FC curves indicates some glassiness in the co-substituted samples. In addition to the observed distortion in crystal structure, a considerable reduction of Fe2+ ions confirmed by XPS has favored enhancement of polarization. (C) 2015 Elsevier B.V. All rights reserved.