Evidence of Bound Magnetic Polaron-Mediated Weak Ferromagnetism in co-doped SnO2 Nanocrystals: Microstructural, Optical, Hyperfine, and Magnetic Investigations
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- 作者：M. S. Inpasalini ; Ravi Kant Choubey ; Samrat Mukherjee
- 刊名：Journal of Electronic Materials
- 出版年：2016
- 出版时间：July 2016
- 年：2016
- 卷：45
- 期：7
- 页码：3562-3569
- 全文大小：1,359 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Optical and Electronic Materials
Characterization and Evaluation Materials
Electronics, Microelectronics and Instrumentation
Solid State Physics and Spectroscopy - 出版者：Springer Boston
- ISSN：1543-186X
- 卷排序：45
文摘
Phase-pure rutile SnO2 nanoparticles doped with various pairs of transition metals such as Fe–Ni, Fe–Mn, Ni–Mn, and Co–Mn have been synthesized using a sol–gel method. Average crystallite size of 22 nm to 29 nm with no impurity secondary phase was observed by x-ray diffraction (XRD) analysis. The morphologies of the particles were studied and their sizes calculated by field-emission scanning electron microscopy (FESEM). Emission at 338 nm in photoluminescence (PL) spectroscopy was observed and attributed to band-edge emission, while the peak at 470 nm was ascribed to doubly ionized oxygen vacancies. Raman spectroscopy confirmed the phase purity of the sample. The effects of oxygen vacancies broaden the Eg mode of the Raman spectrum. In 119Sn Mössbauer spectra, broadened line width was observed and the singlet was attributed to Sn4+ valence state. The interaction between singly ionized oxygen vacancies and 3d dopant ion is the reason behind the ferromagnetic ordering observed in magnetic studies. Spins pinned at the surface orient randomly, which decreases the total moment.KeywordsDilute magnetic semiconductorXRDMössbauer spectroscopymagnetic studies