A study of superexchange interactions in the perovskite Sr2FeRuO6 by Monte Carlo analysis

Abstract

The spin dynamics of the perovskite Sr₂FeRuO₆ which shows spin-glass behaviour below 60 K have been studied by a Monte Carlo analysis, using an isotropic Heisenberg model for a random occupation of the B-sites by Fe and Ru. It is shown that a comparatively small antiferromagnetic next-nearest-neighbour spin interaction between Fe and Ru spins can lead to spin frustration and a form of spin clustering which precludes the observation of long-range magnetic order. This in turn leads to a separation of the field-cooled and zero-field-cooled magnetisation, to magnetic hysteresis, and to relaxation in the ⁵⁷Fe Mössbauer spectrum.