Crossover from three-dimensional to two-dimensional systems in the nonequilibrium zero-temperature random-field Ising model

We present extensive numerical studies of the crossover from three-dimensional to two-dimensional systems in the nonequilibrium zero-temperature random-field Ising model with metastable dynamics. Bivariate finite-size scaling hypotheses are presented for systems with sizes L x L x l which explain the size-driven critical crossover from two dimensions (l = const, L -> infinity) to three dimensions (l alpha L -> infinity). A model of effective critical disorder R-c(eff) (l, L) with a unique fitting parameter and no free parameters in the R-c(eff) (l, L -> infinity) limit is proposed, together with expressions for the scaling of avalanche distributions bringing important implications for related experimental data analysis, especially in the case of thin three-dimensional systems.