Structural, optical, and ferromagnetic properties of Co-doped TiO2 films annealed in vacuum
Structural, optical, and ferromagnetic properties of Co-doped TiO2 films annealed in vacuum
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DOI：
10.1063/1.3319556
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发表时间：
2010-03
影响因子：
3.2
通讯作者：
Jianping Xu;S. Shi;Lan Li;Xiaosong Zhang;Yaxin Wang;Xi-ming Chen;Jianfeng Wang;L. Lv;Fengming Zhang;W. Zhong
中科院分区：
文献类型：
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作者：
Jianping Xu;S. Shi;Lan Li;Xiaosong Zhang;Yaxin Wang;Xi-ming Chen;Jianfeng Wang;L. Lv;Fengming Zhang;W. Zhong
采用溶胶-凝胶旋涂法制备了多晶CoxTi 1 − xCoxO 2（x=0-0.06）薄膜。Co掺杂对结构、光学和磁性的影响进行了研究。结果表明，在真空热处理过程中，薄膜中的氧空位和/或缺陷产生。Co掺杂降低晶体质量并抑制晶粒生长。由于Co的引入，光致发光（PL）谱变弱，带隙发射发生蓝移。PL光谱显示Co的溶解度低于0.02。在300 K时，饱和磁化强度约为1.8 μB/Co，与Co的浓度无关，该值近似等于块体金属钴的平均磁矩（1.75 μB/Co）。零场冷却/场冷却测量表明，室温铁磁性Co掺杂的TiO 2薄膜是不是材料的本征性质。通过X射线光电子能谱和扫描电子显微镜证实了Co金属的存在。
Polycrystalline anatase Ti1−xCoxO2 (x=0–0.06) films have been fabricated by sol-gel spin coating. The effects of Co doping on the structural, optical, and magnetic properties are investigated. It is shown that oxygen vacancies and/or defects in the films are generated during thermal treatment in vacuum. Co doping reduces crystal quality and inhibits crystalline grain growth. Due to the introduction of Co, photoluminescence (PL) spectra become weak and the band gap emission has a blueshift. PL spectra reveal that the solubility of Co is lower than 0.02. At 300 K, the saturated magnetization is around 1.8 μB/Co, which is independent of the concentration of Co. This value is approximately equivalent to the average magnetic moment of bulk metallic cobalt (1.75 μB/Co). Zero-field-cooling/field-cooling measurements indicate that room temperature ferromagnetism in Co-doped TiO2 films is not an intrinsic property of the material. The presence of Co metal is identified by x-ray photoelectron spectroscopy and scann...