中国科技论文在线

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2004年12月30日

【期刊论文】Exchange-coupling interaction, effective anisotropy and coercivity in nanocomposite permanent materials

高汝伟， R.W. Gao， a)， W.C. Feng， H.Q. Liu， B. Wang， W. Chen， G.B. Han， P. Zhang， and H.Li W.Li， Y.Q. Guo， W. Pan， X.M. Li， and M.G. Zhu， X. Li

J. Appl. Phys., Vol. 94, No.1, 1 July 2003，-0001，（）：

-1年11月30日

摘要

The inter-grain exchange-coupling interactions, effective anisotropy, and coercivity in nanocomposite Nd2Fe14B/a-Fe magnets were investigated. The effective anisotropy of nanocomposite magnets has been calculated starting from the statistics of boundaries between magnetically hard-hard, hard-soft, and soft-soft grains. The result shows that the effective anisotropy decreases with reduction in grain size and/or increase in soft phase components. When grain sizes reduce to 4-5nm, Keff decreases to 1/3-1/4 of the ordinary value of K. The coercivity in nanocomposite magnets demonstrates a similar behavior. The decrement of coercivity is mainly due to the reduction of effective anisotropy. Considering the opposite varying trend the remanence demonstrates with respect to the effective anisotropy and the coercivity, we conclude that the mean grain size should be in the range of 10-15nm and the volume fraction of soft phase should be less than 50% in order to achieve high energy product magnets.

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2004年12月30日

【期刊论文】Dependence of the magnetic properties on the alignment magnetic

高汝伟， R.W. Gao A， *， J.C. Zhang A， D.H. Zhang A， Y.Y. Dai a， X.H. Meng b， Z.M. Wang b， Y.J. Zhang b， H.Q. Liu b

Journal of Magnetism and Magnetic Materials 191(1999)97-100，-0001，（）：

-1年11月30日

摘要

The dependence of the hard magnetic properties on the alignment magnetic

HDDR process， Bonded anisotropic magnets， Alignment magnetic field， Hard magnetic property， Maximum energy produc

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2004年12月30日

【期刊论文】Magnetic properties and coercivity mechanism of isotropic HDDR NdFeB bonded magnets with Co and Dy addition

高汝伟， W.Chen a， b， *， R.W. Gao a， M.G. Zhu c， W. Pan c， W. Lic， X.M. Li c， G.B. Han W.C. Feng a， B. Wang a

Journal of Magnetism and Magnetic Materials 261(2003)222-227，-0001，（）：

-1年11月30日

摘要

Isotropic NdDyFeCoB bonded magnets with high coercivity of 1.59MA/m and low temperature coefficient of remanence of -0.056%/K (in the temperature range 298-428 K) were prepared successfully by controlling the HDDR process and adjusting the compositions. The influence of Co and Dy additions on the magnetic properties and the magnetization reversal process in magnet was investigated. The high coercivity in (Nd0.8Dy0.2) 13 (Fe0.875Co0.125) 81 B6 HDDR magnet can be attributed to its unique microstructure and the enhancement of anisotropy field of 2:14:1 phase by substitution of Nd by Dy.

HDDR process， Bonded magnets， Coercivity， Temperature coefficient， Microstructure

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2004年12月30日

【期刊论文】Effects of the degree of grain alignment on the hard magnetic properties of sintered NdFeB magnets

高汝伟， R.W. Gao， D.H. Zhang， H. Li， J.C. Zhang

Appl. Phys. A 67, 353-356 (1998)，-0001，（）：

-1年11月30日

摘要

The effects of the alignment degree of grain "easyaxes" on the hard magnetic properties of NdFeB sintered magnets have been investigated. The results show that the remanence polarisation Jr increases monotonously with an enhancement in the degree of grain alignment (i.e. decrease in the orientation coefficient

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2007年06月14日

【期刊论文】Coercivity and its dependence on the strength of alignment magnetic field in Nd-Fe-B sintered magnets

高汝伟

，-0001，（）：

-1年11月30日

摘要

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