A theory of domain wall retardation in magnets with RE ions

Abstract

A microscopic theory of domain wall mobility in the material of iron-garnet type with rare-earth ions has been formulated. The domain wall mobility appeared to be due to two mechanisms (so-called transverse and longitudinal relaxation) known from the theory of ferromagnetic resonance line width. The theory allows the domain wall mobility to be expressed through normal parameters of the material (anisotropy and exchange energy), those of the rare-earth ion, ion concentration and temperature. Microscopic estimation easily accounts for the difference between the relaxation constants measured in the experiments on magnetic resonance and from the mobility of domain walls. © 1990.