Effect of Annealing Ambience on the Properties of CO2+-Doped ZnO Diluted Magnetic Semiconductors
We report the room-temperature ferromagnetism in Co-doped ZnO films fabricated by the sol-gel method in different annealing ambience. The electrical, magnetic, optical properties and microstructures of these thin films have been characterized systematically, and the correlation between magnetic properties and carrier concentration was established. We have found that this system exhibits ferromagnetism at room temperature either in 02 atmosphere or in O2-N2 mixed atmosphere. Furthermore, the samples annealed in O2-N2 mixed atmosphere have shown obvious discrepancy relative to those annealed in oxygen atmosphere. The coercive field of the sample annealed in O2-N2 mix atmosphere was nearly 300Oe, about two times that of the sample annealed in 02 atmosphere. Additionally, electron concentration was measured at 300K, it showed that the resistivity and electron concentration of the film annealed in O2-N2 mixed atmosphere were 398.1 Ω·cm and 2.6x1018 cm-3 resPectively, however, those test results of the film annealed in O2 atmosphere were 215.9Ω·cm and 5.9x 1018 cm-3 respectively. Thus, the magnetism is driven by electron-mediated ferromagnetism and it is possible to tune ferromagnetism in Co2+: ZnO diluted magnetic semiconductors by controlling the carrier concentrations.
ZnO diluted magnetic semiconductors room temperature ferromagnetism sol-gel annealing
L.Zhang G.L.Xu X.H.Wei G.X.Liu D.Y.Zhao
New Materials Laboratory,School of Material Science and Engineering,Southwest University of Science and Technology,Mianyang 62101 O,Sichuan,China.
国际会议
The 10th International Conference on Ferrites(2008中国国际铁氧体研讨会)
成都
英文
55-58
2008-10-10(万方平台首次上网日期,不代表论文的发表时间)