Critical properties of mixed spin-1 and spin-5/2 with equal and unequal crystal fields

Yigit A., ALBAYRAK E.

CHINESE PHYSICS B, vol.21, no.2, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 21 Issue: 2
  • Publication Date: 2012
  • Doi Number: 10.1088/1674-1056/21/2/020511
  • Journal Name: CHINESE PHYSICS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: mixed spin, Bethe lattice, compensation, ferrimagnet, ISING FERRIMAGNETIC SYSTEM, BETHE LATTICE, PHASE-DIAGRAMS, MODELS
  • Erciyes University Affiliated: Yes

Abstract

The effects of assuming equal or unequal crystal fields (CF) on the phase diagrams of a mixed spin-1 and spin-5/2 system are investigated in terms of the recursion relations on the Bethe lattice (BL). The equal CF case was considered for the coordination numbers q = 3, 4, and 6, while for q = 3 the unequal CF case was also studied. It was found that for the equal CF case, the model exhibits second-order phase transitions and two compensation temperatures for all q, the reentrant behavior for q = 4 and first-order phase transitions and tricritical point (TCP) for q = 6. In the unequal CF case for q = 3, the system yields first-and second-order phase transitions, TCP's, and three compensation temperatures. In addition, the TCP's in a very short range are classified as the stable and unstable ones depending on their free energies.