Room-Temperature Ferromagnetic Ga1−xMnxAs (x ≤ 0.05) Nanowires: Dependence of Electronic Structures and Magnetic Properties on Mn Content

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• 作者：Han Sung Kim ; Yong Jae Cho ; Kang Jun Kong ; Chang Hyun Kim ; Gyeong Bok Chung ; Jeunghee Park* ; Jae-Young Kim ; Jungbum Yoon ; Myung-Hwa Jung^† ; ; Younghun Jo ; Bongsoo Kim ; Jae-Pyoung Ahn
• 刊名：Chemistry of Materials
• 出版年：2009
• 出版时间：March 24, 2009
• 年：2009
• 卷：21
• 期：6
• 页码：1137-1143
• 全文大小：381K
• 年卷期：v.21,no.6(March 24, 2009)
• ISSN：1520-5002

文摘

Ga_1−xMn_xAs nanowires were synthesized with finely controlled Mn contents (x = 0, 0.01, 0.02, 0.03, and 0.05) by the vapor transport method. They consisted of single-crystalline GaAs nanocrystals (avg. diameter = 60 nm) grown along the [111] direction. The Mn doping decreases the lattice constant, most significantly at x 776; 0.03. X-ray photoelectron spectroscopy revealed that as the Mn content increases, the binding energy of Ga 2p shifts to a higher energy, which can be correlated with the hybridization between the Mn²⁺ ions and the holes. X-ray absorption spectroscopy and X-ray magnetic circular dichroism confirmed that the Mn²⁺ ions substitute into the tetrahedrally coordinated Ga sites and that the magnetic moment is maximized at x = 0.03, where the lattice constant is minimized and the binding energy of Ga 2p is maximized. The magnetization measurement revealed that all of these nanowires exhibited room-temperature ferromagnetic behavior, which is also observed most significantly for x 776; 0.03.