The spin‐3/2 blume‐capel model on a honeycomb lattice

The temperature dependences of the magnetization m = 〈〈S〉〉 r and of the moments q = 〈〈 S 2 〉〉 r and r =〈〈 S 3 〉〉 r in the spin‐3/2 Blume‐Capel model on a honeycomb lattice are examined in detail, within the framework of an effective field theory based on the use of a probability distribution that correctly accounts for the single site kinematic relations. A number of characteristic behaviours for their thermal variations are obtained, especially for negative values of the crystal field. Its phase diagram is obtained; besides a second‐order transition line occurring at high temperatures, the phase diagram exhibits a first‐order transition line separating the phases (3/2, 3/2) and (1/2, 1/2).