Laws of approach to magnetic saturation for interacting and isolated spherical and cylindrical defects in isotropic magnetostrictive media

Laws of approach to magnetic saturation are derived for interacting spherical and cylindrical defects in isotropic magnetostrictive media like amorphous materials. The normalized longitudinal magnetic deviation ΔM/M goes as 1/H
²
for both cases, provided all defects have the same sign. For randomly signed defects, 1/H
^5/4
and 1/H
^3/2
laws for spheres and cylinders, respectively. Isolated cylindrical defects obey a 1/H or 1/H
²
law depending on whether the defect is small or large compared to an exchange length.