Saturation approach law for grain-oriented polycrystalline magnetic materials

The saturation approach law in grain-oriented polycrystals of cubic materials is studied, taking into account the magnetic interactions among grains, as a function of the crystalline magnetic anisotropy constants K1and K2, and of a grain dispersion parameter τ. This parameter gives in the two limits and a single crystal and a perfectly isotropic polycrystal, respectively. The effect of internal stresses is also taken into account, and it is shown to have little influence on the saturation approach law, which, in grain-oriented materials, is dominated by the spread of the grain distribution. The obtained results suggest one of the most sensitive methods for determining such a spread in these materials from saturation approach measurements, particularly when τ is very small. The made assumptions on the grain distribution are general enough to obtain as particular cases, the Goss texture, the cubic texture, and the fiber texture. Examples of application of the theory to practical cases of grain-oriented Fe-Si 3- percent laminations are given.