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相互作用和有效各向异性随晶粒尺寸和软、硬磁性晶粒尺寸比(Ds:Dh)的关系.软-硬磁性晶粒间的有效各向异性常数可以用软、硬磁性相的平均各向异性常数的统计平均值表示.当晶粒尺寸大于其铁磁交换长度时,晶粒分为有、无交换耦合两部分.无交换耦合部分的各向异性常数为通常的K1,而耦合部分的各向异性常数随到晶粒表面的距离而变化.研究结果表明:软-硬磁性晶粒间的有效各向异性随晶粒尺寸的减小而下降,随着软、硬磁性晶粒尺寸比值(Ds:Dh)的减小而增加.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,软磁性晶粒尺寸为10 nm左右.
参考文献
| [1] | R.Skomski, J.M.D.Coey, Giant Energy Product in Nanostructured Two-Phase Magnets, Phys.Rev.B., 48,15812(1993) |
| [2] | GAO Ruwei, FENG Weicun, CHEN Wei, WANG Biao, HAN Guangbing, ZHANG Peng, Exchange-Coupling Interaction and Effective Anisotropy in Nanocomposite Permanent Materials, Chinese Science Bulletin,47(4), 1166(2002) |
| [3] | G.Herzer, Grain Size Dependence of Coercivity and Permeability in Nanocrystalline Ferromagnets,IEEE.Trans.on Mag., 26, 1397(1990) |
| [4] | R.Fischer, T.Schrefl, H.Kronmiüller, J.Fidler, Grain-Size Dependence of Remanence and Coercive Field of Isotropic Nanocrystalline Composite Permanent Magnets, J.Magn. Magn. Mater., 153, 35(1996) |
| [5] | H.Kronmiüler, R.Fischer, M.Seeger, A.Zern, Micromagnetism and Microstructure of Hard Magnetic Materials, J.Phys. D: Appl. Phys., 29, 2274(1996) |
| [6] | X.K.Sun, Zhang Jian, Chu Yelong, Lin Wei, Cui Baozhi, Zhang Zhidong, Dependence of Magnetic Properties on Grain Size of α-Fe in Nanocomposite (Nd, Dy) (Fe, Co, Nb, B)5.5/α-Fe Magnets, Appl. Phys. Lett., 74,1740(1999) |
| [7] | Zuocheng Wang, Maocai Zhang, Fubiao Li, Shouzeng Zhou, Run Wang, Wei Gong, High-Coercivity (NdDy)2 (FeNb)14B-α-Fe Nanocrystalline Alloys, J.Appl. Phys., 81, 5097(1997) |
| [8] | HAN Guangbing, GAO Ruwei, FENG Weicun, LIU Hanqiang, WANG Biao, ZHANG Peng, CHEN Wei,Effective Anisotropy and Coercivity in Nanocrystalline Single-Phase NdFeB Permanent Magnetic Material,Science in China (Series G), 46(4), 398(2003) |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%