An expression of anisotropy at grain boundary suitable for different coupling conditions was given, based upon which the effective anisotropy between soft and hard grains <Ksh> was calculated in nanoscaled magnetic materials. The results showed that <Ksh> increased rapidly first, then the increase became slow, and <Ksh> decreased with increasing Ds for the same value of Dh. <Ksh> decreased with increasing Ds for all given Dh, and the decrease rate became slow with increasing Dh. In order to obtain higher effective anisotropy between magnetically soft and hard grains, Dh should not be less than 25nm, and Ds should be about 10nm.

Anisotropy at Nano-Grain Boundary and Effective Anisotropy between Magnetically Soft and Hard Nano-Grains. Y.Sun, M.Liu, G.B.Han, R.W.Gao: Journal of Magnetism and Magnetic Materials, 2008, 320[5], 760-2