Critical properties of a 3D Ising model with a quenched disorder

Static critical properties of the 3D dilute quenched Ising model on a cubic lattice are studied by the Monte Carlo methods. The calculations were carried out for systems with periodic boundary conditions and with spin concentrations p = 1.0, 0.95, 0.9, 0.8, 0.6. Systems with linear dimensions L x L x L (L = 20-60) were investigated. The static critical exponents of the specific heat, susceptibility, magnetization, and the exponent of the correlation radius in the interval of concentrations p studied are calculated on the basis of the finite-size scaling theory. The problem of the universality classes of the critical behavior for three-dimensional dilute systems is considered.