CORRELATED-EFFECTIVE-FIELD TREATMENT OF SPIN-ONE ISING-MODELS

A new version of correlated effective-field theory is applied to a study of the spin-one Ising models, namely the Blume-Capel and Blume-Emery-Griffiths modesl, using the Honmura-Kaneyoshi differential operator technique. This method is illustrated in a honeycomb lattice by investigating the phase diagram, the magnetization, the correlated effective-field parameter and the short-range order parameter. The theory correctly accounts for many physical quantities and leads to results that are quite superior, and in some aspects different, to those of the previous works. © 1990.