Microstructural evolution and its influence on the magnetic properties of CoFe2O4 powders during mechanical milling

被引:120
作者
Liu, B. H.
Ding, J. [1 ]
Dong, Z. L.
Boothroyd, C. B.
Yin, J. H.
Yi, J. B.
机构
[1] Natl Univ Singapore, Fac Engn, Dept Mat Sci & Engn, Singapore 117576, Singapore
[2] Natl Univ Singapore, Dept Chem, Fac Sci, Singapore 119260, Singapore
[3] Nanyang Technol Univ, Sch Mat Sci & Engn, Singapore 639798, Singapore
[4] Inst Mat Res & Engn, Singapore 117602, Singapore
来源
PHYSICAL REVIEW B | 2006年 / 74卷 / 18期
关键词
D O I
10.1103/PhysRevB.74.184427
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
A high coercivity of up to 5.1 kOe was induced in a large-grained CoFe2O4 powder after milling for a short time (1.5 h). It was found that the initial grain (particle) size played an important role in the microstructural evolution and in the magnetic properties of the milled CoFe2O4 materials. The milling-induced microstructural evolution was analyzed using x-ray diffraction and transmission electron microscopy. The results indicated that the milling-induced high coercivity was associated with the highly-strained and defective microstructure. The enhancement in magnetic anisotropy was observed in large-grained CoFe2O4 after milling, which might be mainly attributed to the stress anisotropy. In order to understand the coercivity mechanisms, detailed magnetic studies were carried out by the investigation of the field-dependent magnetization (demagnetization) behaviors and the magnetization reversal processes based on both the micromagnetic model and the phenomenological model. The results revealed that a domain wall pinning-controlled mechanism was responsible for the milling-induced high coercivity in CoFe2O4 materials.
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页数:10
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