Zeitschrift für Physik B Condensed Matter

, Volume 77, Issue 2, pp 339–341 | Cite as

Two-dimensional mixed spin Ising models with bond dilution and random ±J interactions

  • N. Benayad
  • A. Klümper
  • J. Zittartz
  • A. Benyoussef
Article

Abstract

Using the finite cluster approximation we study a mixed spin model (spins Φ=1/2 andS=1) on a square lattice with nearest-neighbour and crystal field interactions. The nearest-neighbour couplingsKijare assumed to be independent random variables with distribution,P(Kij)=pδ(KijK)+(1−p)δ(Kij−αK), whereK>0. We investigate the cases α=0 and α=−1 corresponding to bond dilution and to random ±J interactions, respectively. In certain ranges ofp the phase diagrams exhibit tricritical behaviour and reentrance.

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Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • N. Benayad
    • 1
  • A. Klümper
    • 1
  • J. Zittartz
    • 1
  • A. Benyoussef
    • 2
  1. 1.Institut für Theoretische PhysikUniversität zu KölnKöln 41Federal Republic of Germany
  2. 2.Faculté des Sciences, Laboratoire de MagnétismeUniversité deRabatRabatMorocco

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