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

Systems with an arbitrary dependence of exchange integral on the distance b etween atoms which are randomly scattered in an amorphous substance are inv estigated by averaging over random fields of interaction in the framework o f the Ising model. This method is also used for describing long-term magnet ization relaxation in a system of single-domain particles scattered in a no nmagnetic matrix. Random field distribution functions are obtained for the dipole-dipole and the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interactions. L ong-term relaxation in macrospin glasses is investigated. (C) 2001 MAIK "Na uka/Interperiodica".