Disorder effects in Ising metamagnetic phase transition

The thermodynamics of randomly quenched disordered Ising metamagnet has been studied by Monte Carlo simulations. The disorder has been implemented either by inserting nonmagnetic impurity or by uniformly distributed quenched random magnetic field. The staggered magnetisation ([Formula: see text]) (calculated from the sublattice magnetisation) and the corresponding staggered susceptibility ([Formula: see text]) are studied as functions of the temperature ([Formula: see text]). The antiferromagnetic phase transition has been found while cooling the system from the high temperature paramagnetic phase. The transition temperature (or pseudocritical temperature ([Formula: see text])) has been found to decrease as the concentration ([Formula: see text]) of nonmagnetic impurity increased. blueThe nonmagnetic impurity dependent staggered magnetisation has been found to show the scaling behaviour [Formula: see text] (with [Formula: see text], [Formula: see text] and [Formula: see text]) obtained through the data collapse. The zero temperature staggered magnetisation ([Formula: see text]) has been found to decrease linearly. The critical temperature([Formula: see text]) is showing a linear ([Formula: see text]) dependence with the concentration ([Formula: see text]) of nonmagnetic impurity. The antiferromagnetic phase transition has been found to take place at lower temperature for the higher value of the width ([Formula: see text]) of the uniformly distributed quenched random field. blueThe critical temperature ([Formula: see text]) has been found to show the nonlinear dependence ([Formula: see text]) on the width ([Formula: see text]) of the uniformly distributed random magnetic field. The extrapolation (both for [Formula: see text] and [Formula: see text]) restores the Neel temperature of three dimensional pure Ising antiferromagnet.