纳米软、硬磁性晶粒间的交换耦合及其有效各向异性

功能材料与器件学报 , 2005, 11(4): 401-405. doi: 10.3969/j.issn.1007-4252.2005.04.001

纳米软、硬磁性晶粒间的交换耦合及其有效各向异性

韩广兵 ^1, , 高汝伟 ^2, , 冯维存 ^3, , 刘汉强 ^4, , 白岗 ^5,

1.山东大学物理与微电子学院,济南,250100

2.山东大学物理与微电子学院,济南,250100

3.山东大学物理与微电子学院,济南,250100

4.山东大学物理与微电子学院,济南,250100

5.山东大学物理与微电子学院,济南,250100

基金项目: 国家博士基金(20040422012) 中国科学院资助项目(50371046) 国家科技攻关项目(2002AA324050,2002AA302602)

关键词：交换耦合相互作用 , 有效各向异性 , 纳米晶粒

Exchange-coupling interaction and effective anisotropy between magnetically soft and hard nano-grains

Keywords： exchange-coupling interaction , effective anisotropy , nano-grain

以软磁性相α-Fe和硬磁性相Nd2Fe14B为例,研究了软、硬磁性晶粒间的交换耦合作用和有效各向异性常数随晶粒尺寸的变化关系.由于晶粒间的交换耦合作用,晶粒可分为晶粒内部无界面交换耦合作用影响和晶粒表面有界面交换耦合作用影响两部分,其各向异性常数为两部分的统计平均值.计算结果表明:对固定的软磁性晶粒尺寸Ds, 随硬磁性晶粒尺寸Dh一致增加;对固定的Dh, 随Ds一致减小.为使软、硬磁性晶粒间的有效各向异性常数Keff 保持较高的值,应控制硬磁性晶粒大于35 nm,软磁性晶粒在10 nm 左右.

The effects of grain size on the effective anisotropy constant between the exchange-coupled magnetically soft (α-Fe) and hard (Nd2Fe14B) nano-grains were investigated. Considering the existence of the interfacial exchange coupling between grains, the grain can be divided into two parts: inner part without interfacial exchange-coupling effects (uncoupled) and interfacial part with interfacial exchange coupling effects (coupled). For the given soft grain size Ds, increases with the increasing hard grain size Dh, and then approaches the magnetic anisotropy of the hard phase. For the given Dh, increases with decreasing Ds. A large is predicted in nanocomposite for the hard grain size larger than 35 nm and the soft grain size about 10 nm.

参考文献

[1]	Coehoorn R;Mooij D B De;Waard C De .Melt spun permanent magnet materials containing Fe3B as the main phase[J].Journal of Magnetism and Magnetic Materials,1989,80:101-104.
[2]	Kneller E.F.;Hawig R. .The exchange-spring magnet: a new material principle for permanent magnets[J].IEEE Transactions on Magnetics,1991(4):3588-3560.
[3]	Skomski R;Coey J M .Giant energy product in nanostructured two-phase magnets[J].Physical Review B,1993,48:15812-15816.
[4]	Sun X K;Zhang Jian;Chu Yelong et al.Dependence of magnetic properties on grain size of α-Fe in nanocomposite (Nd, Dy)(Fe, Co, Nb, B)5 5/α-Fe magnets[J].Applied Physics Letters,1999,74:1740-1742.
[5]	Betancourt RJI.;Davies HA. .Effect of the grain size on the magnetic properties of nanophase REFeB alloys[J].Journal of Magnetism and Magnetic Materials,2002(1/2):6-9.
[6]	Exchange-coupling interaction, effective anisotropy and coercivity in nanocomposite permanent materials[J].Journal of Applied Physics,2003(1):664-668.
[7]	Han GB;Gao RW;Yan SS;Liu HQ;Fu S;Feng WC;Li W;Li XM .Effect of exchange-coupling interaction on the effective anisotropy in nanocrystalline Nd2Fe14B material[J].Journal of Magnetism and Magnetic Materials,2004(1):6-10.
[8]	Herzer G. .Grain size dependence of coercivity and permeability in nanocrystalline ferromagnets[J].IEEE Transactions on Magnetics,1990(5):1397-1402.
[9]	Arcas J.;Barandiaran JM.;Prados C.;Vazquez M.;Marin P. Neuweiler A.;Hernando A. .Soft to hard magnetic anisotropy in nanostructured magnets[J].Physical Review.B.Condensed Matter,1998(9):5193-5196.
[10]	Kronmuller H.;Seeger M.;Zern A.;Fischer R. .MICROMAGNETISM AND MICROSTRUCTURE OF HARD MAGNETIC MATERIALS[J].Journal of Physics, D. Applied Physics: A Europhysics Journal,1996(9):2274-2283.
[11]	Schrefl T.;Fidler J. .Finite element modeling of nanocomposite magnets[J].IEEE Transactions on Magnetics,1999(5):3223-3228.
[12]	Wang ZC.;Li FB.;Zhou SZ.;Wang R.;Gong W.;Zhang MC. .HIGH-COERCIVITY (NDDY)(2)(FENB)(14)B-ALPHA-FE NANOCRYSTALLINE ALLOYS[J].Journal of Applied Physics,1997(8 Pt.2b):5097-5099.

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