| Autor: |
G. Z. Xing, Y. H. Lu, Y. F. Tian, J. B. Yi, C. C. Lim, Y. F. Li, G. P. Li, D. D. Wang, B. Yao, J. Ding, Y. P. Feng, T. Wu |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| Předmět: |
|
| Zdroj: |
AIP Advances, Vol 1, Iss 2, Pp 022152-022152-14 (2011) |
| Druh dokumentu: |
article |
| ISSN: |
2158-3226 |
| DOI: |
10.1063/1.3609964 |
| Popis: |
To shed light on the mechanism responsible for the weak ferromagnetism in undoped wide band gap oxides, we carry out a comparative study on ZnO thin films prepared using both sol-gel and molecular beam epitaxy (MBE) methods. Compared with the MBE samples, the sol-gel derived samples show much stronger room temperature ferromagnetism with a magnetic signal persisting up to ∼740 K, and this ferromagnetic order coexists with a high density of defects in the form of zinc vacancies. The donor-acceptor pairs associated with the zinc vacancies also cause a characteristic orange-red photoluminescence in the sol-gel films. Furthermore, the strong correlation between the ferromagnetism and the zinc vacancies is confirmed by our first-principles density functional theory calculations, and electronic band alteration as a result of defect engineering is proposed to play the critical role in stabilizing the long-range ferromagnetism. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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