THE CRITICAL-BEHAVIOR OF THE 2-DIMENSIONAL DILUTE ISING MAGNET

Two-dimensional random-bond Ising models of L × L spins are simulated extensively. In the randomness dominated critical region, the size dependences of the specific heat, C, the susceptibility, χ, and the magnetization, m, at critically are in very good agreement with the analytic predictions, C ≈ ln ln L, χ ≈ Lif 7 4, and m ≈ L -1 8. The temperature dependences of χ and m close to the critical point can be described by power laws with the exponents of the perfect model, modified by logarithmic corrections. © 1990.