Bethe lattice consideration of the antiferromagnetic spin-1 Ising model

The antiferromagnetic Blume-Capel spin-1 Ising model in an external magnetic field is considered on the Bethe lattice. Using an iteration technique, we obtain the plots of magnetization versus temperature for different external fields and construct the resulting phase diagrams. Comparison is made between the results of this study and previous mean-field and Monte Carlo simulations. It was found that the decomposition of the tricritical point into a critical end point and a critical point appears in the phase diagram for q = 6. (C) 2004 Elsevier B.V. All rights reserved.