Correlated Effective‐Field Treatment of the Blume‐Capel Model with Half‐Integer Spins

Correlated effective‐field theory and effective‐field theory with use of exact spin identities are applied to a study of the half‐integer spins, namely the Blume‐Capel model for spin‐3/2 and spin‐5/2. These methods are illustrated in a honeycomb lattice by investigating the phase diagram, the magnetization, the quadrupolar moment, and the correlated effective‐field parameter. The theory correctly accounts for many physical quantities and leads to results that are quite superior to those of previous works.