Determination of initial magnetization curve from crystallites size and effective anisotropy field

It is shown that in YIG the magnetization in low fields is due to the same mechanisms for the whole temperature range to the Curie point. At a given temperature the magnetization curves for different samples can be reduced to a single curve by taking into account the grain size. The interpretation is based on a model proposed earlier by Globus: the value of the reversible magnetization would be determined by the wall bulging, the value of the nonreversible magnetization by the wall displacement inside a spherical grain. For different temperatures a single reduced line is obtained by introducing the saturation magnetization and the effective anisotropy field, which is calculated from the susceptibility measured on a sample with single domain grains. So, it is possible to obtain a single magnetization curve which characterizes the composition.