STATISTICAL MECHANICS OF FINITE ISING MODEL WITH HIGHER SPIN

The partition functions of the finite Ising models of spin S=1, 3/2, 2, 5/2 and 3 have been calculated by a high speed computer. The periodicity condition at the boundaries has been imposed, and only the nearest neighbor interaction has been assumed. The specific heats of these finite systems have been calculated as a function of temperature. The maxima of the specific heat increase proportionally to long N in the two-dimensional Ising model with spin S=1, N being the number of lattice points, which indicates that the specific heat for the above lattice has a singularity such as [formula omitted]. The difference (B+-B-) has been estimated from the asymmetric distribution of the zeros of the partition function in the complex temperature plane. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.