An exact formulation of the Blume-Emery-Griffiths model on a two-fold Cayley tree model


Albayrak E. , Keskin M.

EUROPEAN PHYSICAL JOURNAL B, cilt.24, ss.505-510, 2001 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 24 Konu: 4
  • Basım Tarihi: 2001
  • Doi Numarası: 10.1007/s10051-001-8704-3
  • Dergi Adı: EUROPEAN PHYSICAL JOURNAL B
  • Sayfa Sayısı: ss.505-510

Özet

A two-fold Cayley tree graph with folly q-coordinated sites is constructed and the spin-1 Ising Blume-Emery-Griffiths model on the constructed graph is solved exactly using the exact recursion equations for the coordination number q = 3. The exact phase diagrams in (kT/J, K/J) and (kT/J, D/J) planes are obtained for various values of constants D/J and K/J, respectively. and the tricritical behavior is found. It is observed that when the negative biquadratic exchange (K) and the positive crystal-field (D) interactions are large enough. the tricritical point disappears in the (kT/J, K/J) plane. On the other hand, the system always exhibits a tricritical behavior in the phase diagram of (kT/J, D/J) plane.