Oxygen vacancies contained TiO2 spheres: facile fabrication and enhanced ferromagnetism
Oxygen vacancies contained TiO2 spheres: facile fabrication and enhanced ferromagnetism
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DOI：
10.1007/s11051-012-1030-2
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发表时间：
2012-08-01
影响因子：
2.5
通讯作者：
Liu, Min
中科院分区：
文献类型：
--
作者：
Li, Hongmei;Zeng, Yangsu;Liu, Min
以钛粉为原料，用一种简便的方法成功地合成了尺寸在400 nm左右的均匀的二氧化钛微球。得到的二氧化钛球体在热处理前都表现出良好的锐钛矿型结构。通过UV-Vis光谱和XPS光谱的测量，证明所制备的二氧化钛微球中含有大量的氧空位(Vo)。退火热处理后，VO的浓度明显降低。磁性测量结果表明，纳米二氧化钛微球的铁磁性随退火温度的升高而降低，说明VO的浓度越大，铁磁性越强。这些结果表明，未掺杂的二氧化钛中的FM可以归因于氧空位。此外，简单、低成本的合成方法使该产品成为很有前途的自旋电子器件材料。
Uniform TiO2 spheres with a size of around 400 nm have been successfully synthesized by a facile approach from Ti powders. The obtained TiO2 spheres exhibit a good anatase structure ever before the annealing treatment. Through the measurement of UV-Vis spectra and XPS spectra, it was proved that the as-obtianed TiO2 spheres contained a lot of oxygen vacancies (Vo). After annealed, the concentration of Vo are decreased seriously. Magnetic measurements showed that the ferromagnetism (FM) of the TiO2 spheres also decreased with the annealing treatment, which informs the larger the concentration of Vo is, the stronger the FM becomes. These results indicate that the FM in undoped TiO2 can be contributed to oxygen vacancies. Moreover, the facile and low cost synthesis method makes the products to be promising materials for spintronic devices.