机构地区: 中国科学院物理研究所
出 处: 《物理学报》 2003年第3期708-712,共5页
摘 要: 畴壁钉扎模型的矫顽力可以表示为Hc=αpink2K1 μ0 Ms-NeffMs,计算了微结构参数αpink 随面缺陷内磁性参数A′和K′1 的变化情况 .结果表明 ,αpink 可以在很宽的范围里取值 .结合纳米单相Nd2 Fe1 4B磁体 ,研究了晶粒边界的磁性参数和晶界厚度对αpink 的影响 ,当A′ A =0 5 ,K′1 K1 =0 1,以及晶界厚度r0 =3 32nm时 ,αpink 最大 .同时研究了纳米复相Nd2 Fe1 4B α Fe磁体的αpink 随α Fe晶粒尺寸r0 的变化情况 ,当r0 =7nm时 ,αpink 最大 . The coercive force of the domain-wall pinning model can be expressed as H-c = alpha(k)(pin) 2K(1) /mu(0)M(s) - N-eff M-s. The dependences of the microstructure parameter alpha(k)(pin) on the exchange and anisotropy constants of inhomogeneities are discussed in this paper - The results show that there is a wide range of the alpha(k)(pin) values. The effects of magnetic parameter and thickness of Nd-2 Fe-14 B grain boundary on the alpha(k)(pin) are also studied. It was found that alpha(k)(pin) reaches the maximum where A'/A = 0.5, K-1'/K, = 0.1 and the grain-boundary thickness r(0) = 3.32nm. alpha(k)(pin) of nanocomposite Nd-2 Fe-14 B/alpha-Fe magnets reaches the maximum when the grain size r(0) is 7nm.