Mixed spin-2 and spin-5/2 Blume-Capel model


PHYSICS LETTERS A, vol.372, no.4, pp.361-366, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 372 Issue: 4
  • Publication Date: 2008
  • Doi Number: 10.1016/j.physleta.2007.07.056
  • Journal Name: PHYSICS LETTERS A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.361-366
  • Erciyes University Affiliated: Yes


The influence of increasing the coordination number q on the phase diagrams of the mixed spin-2 and spin-5/2 Blume-Capel Ising ferrimagnetic system with two crystal-field interactions, D-A for spin-2 and D-B for spin-5/2, is investigated on the Bethe lattice by using the exact recursion equations. The phase diagrams are obtained for the case with equal crystal field strengths when q = 3, 4 and 6 on the (kT/|J|, D/|J|) planes and for the case with unequal crystal field strengths on the (kT/|J|, D-A/|J|) and (kT/|J|, D-B/|J|) planes for various values of D-B/|J| and D-A/|J|, respectively, for q = 4 and 6. Besides the second-order lines, the model presents three types of first-order phase transition lines; one of them ends on the compensation lines (q = 3), the other one ends at a critical end point (q = 4) and last one terminates at a tricritical point (q = 6) for the case with equal crystal field strengths. In this case we have also observed up to four compensation temperatures when q = 6. Besides the second-order, tricritical and compensation lines, the system presents two types of the first-order lines one of them ending at a tricritical point and the other one ending at an isolated point when unequal crystal field values are taken. (C) 2007 Elsevier B.V. All rights reserved.