THE SHIFT EXPONENT OF THE LAYERED SQUARE-LATTICE ISING-MODELS

Layered square-lattice ferromagnetic Ising models (infinity x infinity x n lattices) are studied by the Monte Carlo simulation with the peri odic boundary condition(n = 3 similar to 8) and with the free boundary condition (n = 4 similar to 14) in the n-direction. The results show the dimensionality crossover from the square-lattice Ising model to th e simple-cubic Ising model. The shift exponent lambda shows the size d ependent behavior contrary to the previous results, and goes to about lambda similar to 1.60 in the limit, n --> infinity, for both boundary conditions, which is consistent with lambda = 1/v(3d).