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标题：Reduction of dopant ions and enhancement of magnetic properties by UV irradiation in Ce-doped TiO ₂
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作者：Tai-Sing Wu ; Leng-You Syu ; Bi-Hsuan Lin 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2021
卷号：11
DOI：10.1038/s41598-021-87115-z
语种：English
出版社：Springer Nature
摘要：We report the experimental observation of and theoretical explanation for the reduction of dopant ions and enhancement of magnetic properties in Ce-doped TiO 2 diluted magnetic semiconductors from UV-light irradiation. Substantial increase in Ce 3+ concentration and creation of oxygen vacancy defects in the sample due to UV-light irradiation was observed by X-ray and optical methods. Magnetic measurements demonstrate a combination of paramagnetism and ferromagnetism up to room temperatures in all samples. The magnetization of both paramagnetic and ferromagnetic components was observed to be dramatically enhanced in the irradiated sample. First-principle theoretical calculations show that valence holes created by UV irradiation can substantially lower the formation energy of oxygen vacancies. While the electron spin densities for defect states near oxygen vacancies in pure TiO 2 are in antiferromagnetic orientation, they are in ferromagnetic orientations in Ce-doped TiO 2. Therefore, the ferromagnetically-oriented spin densities near oxygen vacancies created by UV irradiation are the most probable cause for the experimentally observed enhancement of magnetism in the irradiated Ce-doped TiO 2.