Defect controlled room temperature ferromagnetism in Co-doped barium titanate nanocrystals
Defect controlled room temperature ferromagnetism in Co-doped barium titanate nanocrystals
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DOI：
10.1088/0957-4484/23/2/025702
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发表时间：
2012-01
期刊：
影响因子：
3.5
通讯作者：
S. Ray;Yury V. Kolen’ko;K. Kovnir;O. Lebedev;S. Turner;T. Chakraborty;R. Erni;Tomoaki Watanabe;G. Tendeloo;M. Yoshimura;M. Itoh
中科院分区：
文献类型：
--
作者：
S. Ray;Yury V. Kolen’ko;K. Kovnir;O. Lebedev;S. Turner;T. Chakraborty;R. Erni;Tomoaki Watanabe;G. Tendeloo;M. Yoshimura;M. Itoh
氧化物纳米晶中的缺陷介导的高温铁磁性是这项工作的中心特征。在这里，我们报告的发展室温铁磁性的纳米尺寸的钴掺杂钛酸钡颗粒的尺寸约为14 nm，通过溶剂热干燥法合成。X射线衍射与最先进的电子显微镜技术相结合，证实了本征掺杂的钴到钛酸钡。室温铁磁性的发展被追踪到不同的施主缺陷，即氧位点处的羟基（）和氧空位（），以及它们在纳米晶表面和芯部的相对浓度，这可以通过合成后干燥和热处理来控制。
Defect mediated high temperature ferromagnetism in oxide nanocrystallites is the central feature of this work. Here, we report the development of room temperature ferromagnetism in nanosized Co-doped barium titanate particles with a size of around 14 nm, synthesized by a solvothermal drying method. A combination of x-ray diffraction with state-of-the-art electron microscopy techniques confirms the intrinsic doping of Co into BaTiO3. The development of the room temperature ferromagnetism was tracked down to the different donor defects, namely hydroxyl groups at the oxygen site () and oxygen vacancies (), and their relative concentrations at the surface and the core of the nanocrystal, which could be controlled by post-synthesis drying and thermal treatments.