THE SPIN-1 BLUME-CAPEL MODEL WITH ALTERNATINGLY CHANGING BILINEAR EXCHANGE INTERACTIONS BETWEEN SUBLATTICES


Albayrak E.

INTERNATIONAL JOURNAL OF MODERN PHYSICS B, cilt.26, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 26 Konu: 5
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1142/s0217979211102216
  • Dergi Adı: INTERNATIONAL JOURNAL OF MODERN PHYSICS B

Özet

The spin-1 Blume-Capel model is studied on a Bethe lattice which is divided into two sublattices A and B. Alternatingly changing bilinear exchange interactions, JAB and JBA, between the sublattices, i.e., between the nearest-neighbor shell spins, are assumed. The phase diagrams of the model are studied on the (JAB, T) planes for given values of JBA, crystal fields D and the coordination numbers q = 3, 4 and 6. It was found that the model either displays only second-order phase transition lines at higher crystal field values or second-and first-order phase transitions lines combined at tricritical points at lower negative crystal fields. It was also found that the tricritical points move to higher temperatures and to higher values of JAB as the crystal field becomes more negative.