The spin-2 antiferromagnet on the Bethe lattice
Erciyes University, Department of Physics, 38039, Kayseri, Turkey
Corresponding author: a email@example.com
Revised: 18 April 2006
Published online: 21 August 2006
The complete phase diagrams of the antiferromagnetic spin-2 Blume-Capel Ising system is studied on the Bethe lattice by the use of exact recursion relations. In order to specify the states of the system, i.e. the different spin configurations, the ground state phase diagram is obtained on the (H/|J|, D/|J|) plane corresponding to the reduced external magnetic and crystal fields, respectively. As a result, the thermal change of the order-parameters, the magnetisations belonging to the two sublattice system, was investigated to obtain the full phase diagrams of the system on the (H/|J|, kT/|J|) planes. The behavior of the order-parameters with respect to the external magnetic field was also studied for the given values of D/|J|. Besides the interesting thermal and external magnetic field change of the sublattice magnetisations, the system also exhibits interesting critical behaviors including first- and second-order phase transitions, therefore, triciritical points and the reentrant behavior. The calculations are carried out for the coordination number q=4, corresponding to the square lattice, only.
PACS: 05.50.+q – Lattice theory and statistics (Ising, Potts, etc.) / 05.70.Fh – Phase transitions: general studies / 64.60.Cn – Order-disorder transformations; statistical mechanics of model systems / 75.10.Hk – Classical spin models
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006