Approach to the magnetic saturation in nanocrystalline ferromagnets in the random anisotropy model

Recent experimental data on the magnetization curve M(H) of magnetically soft nanocrystalline Fe73.5Cu1Nb3Si13.5B9 sample are analyzed in terms of the random anisotropy model. Numerical calculations of magnetization are supplemented by a high-field expansion. Near the saturation we get M(H)/M-s = 1 - 4[K](2)/(15M(s)(2)H(2)), where [K] is the averaged anisotropy of crystalline grains, contained in large magnetic domains. Section I is an introduction. In Sec. II, reference data on the model parameters of the nanocrystalline system Fe73.5Cu1Nb3Si13.5B9 are collected in order to justify the model approximations and to prepare the comparison with experimental results. In the two subsequent sections, the results of the calculations are described and discussed. (C) 1998 American Institute of Physics. [S0021-8979(98)28211-9].