Regulation of Magnetic Behavior and Electronic Configuration in Mn-Doped ZnO Nanorods through Surface Modifications

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• 作者：Linjuan Zhang ; Jian-Qiang Wang ; Jiong Li ; Shuo Zhang ; Zheng Jiang ; Jing Zhou ; Jie Cheng ; Tiandou Hu ; Wensheng Yan ; Xiangjun Wei ; Ziyu Wu
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：May 8, 2012
• 年：2012
• 卷：24
• 期：9
• 页码：1676-1681
• 全文大小：400K
• 年卷期：v.24,no.9(May 8, 2012)
• ISSN：1520-5002

文摘

In this research, Mn-doped ZnO nanorods were synthesized by a solvothermal method and their magnetic behavior was tuned from paramagnetism to ferromagnetism via a change in their surface environment. The structure and electronic configuration of Mn ions were investigated by means of X-ray diffraction and X-ray absorption fine structure to understand the surface-controlled magnetic properties. The surface electronic configuration was studied by Mn L_3,2-edge XANES, which were simulated using the ligand field multiplet theory and the ligand-to-metal charge transfer effects. The results pointed out that Mn³⁺ ions occupy distorted tetrahedronal sites near the surface region and different surface modifications produce changes in the Mn 3d-anion p hybridization strength. A midgap state with strong O-2p character has been also recognized at the O K-edge XANES, and the density of such a state is strongly related to the observed ferromagnetism. This research represents a novel promising route for tuning the magnetic behavior of nano-dilute magnetic semiconductor systems via surface atomic changes.

Keywords:

dilute magnetic semiconductor; surface modification; X-ray absorption spectroscopy