Distribution function for random interaction fields in disordered magnets: Spin and macrospin glass

Abstract

Systems with an arbitrary dependence of exchange integral on the distance between atoms which are randomly scattered in an amorphous substance are investigated by averaging over random fields of interaction in the framework of the Ising model. This method is also used for describing long-term magnetization relaxation in a system of single-domain particles scattered in a nonmagnetic matrix. Random field distribution functions are obtained for the dipole-dipole and the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interactions. Long-term relaxation in macrospin glasses is investigated.