The synthesis and exchange bias effect of monodisperse NiO nanocrystals  

作　　者：段寒凝 袁松柳 郑先锋 田召明 

机构地区：[1]School of Physics,Huazhong University of Science and Technology

出　　处：《Chinese Physics B》2012年第7期536-540,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 11174092)

摘　　要：Monodisperse NiO nanocrystals with an average particle size of 3 -h 0.4 nm are successfully synthesized by the thermal decomposition of Ni-oleylamine complex in an organic solvent under a continuous 02 flux. The crystalline structure and the morphology of the product are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Magnetization and alternating-current （ac） susceptibility measurements indicate that the structure of the particles can be considered as consisting of an antiferromagnetieally 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 field cooling. This observed exchange bias effect is explained in terms of the exchange interaction between the antiferromagnetie core and the spin-glass-like shell.Monodisperse NiO nanocrystals with an average particle size of 3 -h 0.4 nm are successfully synthesized by the thermal decomposition of Ni-oleylamine complex in an organic solvent under a continuous 02 flux. The crystalline structure and the morphology of the product are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Magnetization and alternating-current （ac） susceptibility measurements indicate that the structure of the particles can be considered as consisting of an antiferromagnetieally 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 field cooling. This observed exchange bias effect is explained in terms of the exchange interaction between the antiferromagnetie core and the spin-glass-like shell.

关 键 词：nanocrystalline materials ANTIFERROMAGNETICS spin glass exchange bias 

分 类 号：TB383.1[一般工业技术—材料科学与工程]