Magnetic dipole moment saturation

The magnetisation of a compound, M, is the dipole moment per unit volume. For ferromagnetic compounds, the saturation magnetisation, Ms, when all of the dipoles are aligned, can be measured and used to estimate the effective magnetic moment on the atoms in the stmcture when the unit cell is known. 

Domains and Below its Curie temperature, a ferromagnetic or ferrimagnetic material is composed of Hysteresis domains —small-volume regions in which all net dipole moments are mutually aligned and the magnetization is saturated (Figure 20.11). 

Using the magnetic form factor of the free Tm ion in the dipole approximation, Neuenschwander and Wachter (1990a,b) find that the saturation magnetization B(Tm) at 1.5 K is 1.8 0.4 Ub, much less than the saturation moment of either Tm or Tm. The temperature dependence of the magnetization is shown in fig. 88. The data can be fitted surprisingly well with the power law... 

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