Eur. Phys. J. B 50, 439-443 (2006)
https://doi.org/10.1140/epjb/e2006-00162-5

Phase diagrams of spin-1 Ising model with bilinear and quadrupolar interactions under magnetic field. Two-particle cluster approximation

Institute for Condensed Matter Physics, 1 Svientsitskii Str., L'viv, 79011, Ukraine

Corresponding author: ^a ost@icmp.lviv.ua

Received: 7 December 2005
Revised: 8 February 2006
Published online: 5 May 2006

Abstract

The spin-1 Ising model with bilinear and quadrupolar short-range interactions under magnetic field is investigated within the two-particle cluster approximation. It is shown that for those values of the quadrupolar interaction when at zero magnetic field the system undergoes a temperature phase transition between quadrupolar and paramagnetic phases, a triple point may exist in the temperature vs. magnetic field phase diagrams, necessarily along with a critical point. It is also shown that the critical points in the temperature vs. magnetic field phase diagrams of the investigated model can be of three types.