Cobalt-Doped TiO2 Nanocrystallites: Radio-Frequency Thermal Plasma Processing, Phase Structure, and Magnetic Properties
Cobalt-Doped TiO2 Nanocrystallites: Radio-Frequency Thermal Plasma Processing, Phase Structure, and Magnetic Properties
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DOI：
10.1021/jp8080047
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发表时间：
2009-05-14
影响因子：
3.7
通讯作者：
Ishigaki, Takamasa
中科院分区：
文献类型：
--
作者：
Li, Ji-Guang;Buechel, Robert;Ishigaki, Takamasa
采用Ar/O-2射频热等离子体氧化技术，以钛酸四丁酯和硝酸钴为前驱体，一步合成了Co2+掺杂的TiO 2纳米粉体。发现Co 2+掺杂稳定地促进金红石结晶。Co2+在TiO 2晶格中的溶解度被确定为约2.0原子%，高于该溶解度CoTiO 3和Co2 TiO 4可以作为杂质相形成。通过各种表征技术，包括高功率XRD，HR-TEM，XPS，排除了金属Co或任何其他铁磁杂质的存在，而纳米粉末显示出室温铁磁性，这被表明是固有的性质。随着Co 2+科尔浓度LIP增加到7 atom %，TiO 2：Co样品的铁磁性能趋于下降，这归因于共掺杂增强了金红石晶化和顺磁杂质的形成。
Co2+-doped TiO2 nanopowders have been synthesized via one-step Ar/O-2 RF thermal Plasma oxidizing mists of liquid precursors containing titanium tetra-n-butoxide and cobalt (II) nitrate. Co2+ doping was found to steadily promote rutile crystallization. The Solubility of Co2+ in the TiO2 lattice was determined to be around 2.0 atom %, above which CoTiO3 and Co2TiO4 may be formed as impurity phases. The existence of metallic Co or any other ferromagnetic impurities were excluded by a variety of characterization techniques, including high-power XRD, HR-TEM, XPS, whereas the nanopowders exhibit room-temperature ferromagnetism, which was indicated to be of intrinsic nature. The ferromagnetic performances of the TiO2:Co samples tend to decrease with increasing the Co2+ Coll tent LIP to similar to 7 atom %, which has been ascribed to the enhanced rutile crystallization by co-doping and the formation of paramagnetic impurities.