摘要
以纳米Nd2Fe14B永磁材料为例,研究了硬磁晶粒间交换耦合相互作用对磁体有效各向异性的影响。结果表明晶粒间交换耦合相互作用随晶粒尺寸的减小而增强,材料的有效各向异性常数Keff,随晶粒尺寸的减小而逐渐下降,Keff随晶粒尺寸的变化与矫顽力的变化规律相似。纳米单相永磁材料有效各向异性的减小是矫顽力降低的主要原因,交换耦合系数αex实际上是各向异性的减小量。为保证纳米Nd2Fe14B材料具有较高的各向异性和矫顽力,晶粒尺寸应不小于30nm。
Effects of exchange-coupling interaction on the effective anisotropy for magnetic hard Nd2Fe14B grain were investigated. The results show that the exchange-coupling interaction between grains makes the effective anisotropy of material, Keff, decrease with the reduction of grain size. The variation of Keff was basically the same as that of coercivity. The decrement of effective anisotropy was the main reason of the reduction of coercivity for nanocrystalline Nd2Fe14B permanent magnetic material. In order to get high anisotropy and coercivity in nanocrystalline Nd2Fe14B permanent material, the grain size should be larger than 30 nm.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2004年第2期159-160,163,共3页
Journal of Functional Materials
基金
国家高技术研究发展计划(863计划)资助项目(2002AA324050
2002AA302602)
国家自然科学基金资助项目(50370625)
