中国物理B ›› 2012, Vol. 21 ›› Issue (7): 78101-078101.doi: 10.1088/1674-1056/21/7/078101

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

The synthesis and exchange bias effect of monodisperse NiO nanocrystals

段寒凝, 袁松柳, 郑先锋, 田召明   

  1. School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • 收稿日期:2011-11-23 修回日期:2011-12-19 出版日期:2012-06-01 发布日期:2012-06-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11174092).

The synthesis and exchange bias effect of monodisperse NiO nanocrystals

Duan Han-Ning(段寒凝), Yuan Song-Liu(袁松柳)†, Zheng Xian-Feng(郑先锋), and Tian Zhao-Ming(田召明)   

  1. School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2011-11-23 Revised:2011-12-19 Online:2012-06-01 Published:2012-06-01
  • Contact: Yuan Song-Liu E-mail:yuansl@hust.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11174092).

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摘要： Monodisperse NiO nanocrystals with an average particle size of 3? 0.4 nm are successfully synthesized by the thermal decomposition of Ni-oleylamine complex in an organic solvent under a continuous O2 flux. The crystalline structure and the morphology of the product are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscope. Magnetization and alternating-current (ac) susceptibility measurements indicate that the structure of the particles can be considered as consisting of an antiferromagnetically ordered core and a spin-glass like surface shell. In addition, both the exchange bias field and the vertical magnetization shift can be observed in this system at 10 K after the field cooling. This observed exchange bias effect is explained in terms of the exchange interaction between the antiferromagnetic core and the spin-glass like shell.

关键词: nanocrystalline materials, antiferromagnetics, spin glass, exchange bias

Abstract: Monodisperse NiO nanocrystals with an average particle size of 3? 0.4 nm are successfully synthesized by the thermal decomposition of Ni-oleylamine complex in an organic solvent under a continuous O2 flux. The crystalline structure and the morphology of the product are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscope. Magnetization and alternating-current (ac) susceptibility measurements indicate that the structure of the particles can be considered as consisting of an antiferromagnetically ordered core and a spin-glass like surface shell. In addition, both the exchange bias field and the vertical magnetization shift can be observed in this system at 10 K after the field cooling. This observed exchange bias effect is explained in terms of the exchange interaction between the antiferromagnetic core and the spin-glass like shell.

Key words: nanocrystalline materials, antiferromagnetics, spin glass, exchange bias

中图分类号:  (Nanocrystalline materials)

  • 81.07.Bc
75.50.Ee (Antiferromagnetics) 75.50.Lk (Spin glasses and other random magnets) 75.30.Et (Exchange and superexchange interactions)