Room-temperature ferromagnetism in Li-doped p-type luminescent ZnO nanorods

被引:142
作者
Chawla, Santa [1 ]
Jayanthi, K. [1 ]
Kotnala, R. K. [1 ]
机构
[1] Natl Phys Lab, New Delhi 110012, India
来源
PHYSICAL REVIEW B | 2009年 / 79卷 / 12期
关键词
Curie temperature; ferromagnetic materials; ferromagnetic resonance; hole density; II-VI semiconductors; impurity states; lithium; magnetic domains; magnetic force microscopy; magnetic moments; nanostructured materials; paramagnetic resonance; photoluminescence; semimagnetic semiconductors; wide band gap semiconductors; zinc compounds; NANOCRYSTALLINE THIN-FILMS; OPTICAL-PROPERTIES; QUANTUM DOTS; SEMICONDUCTORS; ACCEPTOR; OXIDE; LITHIUM;
D O I
10.1103/PhysRevB.79.125204
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We have observed ferromagnetism in Li-doped ZnO nanorods with Curie temperature up to 554 K. Li forms shallow acceptor states in substitutional zinc sites giving rise to p-type conductivity. An explicit correlation emerges between increase in hole concentration with decrease in magnetization and Curie temperature in ZnO:Li. Occurrence of ferromagnetism at room temperature has been established with observed magnetic domain formation in ZnO:Li pellets in magnetic force microscopy and prominent ferromagnetic resonance signal in electron paramagnetic resonance spectrum. Magnetic ZnO:Li nanorods are luminescent, showing strong near UV emission. Substitutional Li atoms can induce local moments on neighboring oxygen atoms, which when considered in a correlated model for oxygen orbitals with random potentials introduced by dopant atom could explain the observed ferromagnetism and high Curie temperature in ZnO:Li nanorods.
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页数:7
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