Mixed spin-
and spin-
Ising models with random nearest-neighbour interactions |
| |
Authors: | N. Benayad,A. Dakhama,A. Klü mper,J. Zittartz |
| |
Abstract: | Using the effective field theory with correlations, we study mixed spin?3/2 and spin?1/2 Ising models with random bonds and crystal-field interactions on the honeycomb lattice. The nearest-neighbour couplings Jij are taken as random variables with distribution P(Jij) = pδ(Jij ? J)+(1 ? p)δ(Jij ? αJ), where J > 0 and |α| ≤ 1. In a certain range of negative values of α, the phase diagrams exhibit re-entrant behaviour. In detail, we investigate separately two kinds of disorder: Bond dilution (α = 0) and random ±J interactions (α = ?1). In both cases, the influence of the an-isotropy on the phase diagrams shows some new outstanding features. |
| |
Keywords: | Mixed spin Ising models Reentrance phenomenon Effective field theory |
|
|