Interfacial structure and kinetics of ordering in weak ferromagnets

The kinetics of domain growth in weak ferromagnets is studied by use of an appropriate set of Langevin equations. Because of the coupling between the order parameters, which arises from the Dzyaloshinsky-Moriya anisotropic interaction, the time evolution of the various correlation functions is coupled even in the linear theory. An analysis of the late stage of the evolution, following a critical quench, in terms of the motion of the interfaces is shown to lead to a $t^{1/2}$ domain-growth law. We have also studied the growth following an off-critical quench from a very high temperature.