| Issue |
J. Phys. Colloques
Volume 49, Number C8, Décembre 1988
Proceedings of the International Conference on Magnetism
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|
|---|---|---|
| Page(s) | C8-1261 - C8-1262 | |
| DOI | https://doi.org/10.1051/jphyscol:19888573 | |
Proceedings of the International Conference on Magnetism
J. Phys. Colloques 49 (1988) C8-1261-C8-1262
DOI: 10.1051/jphyscol:19888573
1 Laboratoire de Magnétisme des surfaces, Université Paris 7, 75251 Paris Cedex 05, France
2 Département de recherches Physiques, T22-E3, Université Paris 6, 75252 Paris Cedex 05, France
J. Phys. Colloques 49 (1988) C8-1261-C8-1262
DOI: 10.1051/jphyscol:19888573
CONTINUOUS VERSUS FIRST ORDER TRANSITION IN DILUTE ISING ANTIFERROMAGNETS IN A FIELD
H. T. Diep1, S. Galam2 et P. Azaria11 Laboratoire de Magnétisme des surfaces, Université Paris 7, 75251 Paris Cedex 05, France
2 Département de recherches Physiques, T22-E3, Université Paris 6, 75252 Paris Cedex 05, France
Abstract
A systematic Monte Carlo investigation of dilute Ising antiferromagnets in a uniform field as function of both dilution and ratio α of nnn to nn interactions on a cubic lattice is presented. A tricritical point is found in the range of dilution 0 ≤ p ≤ 0.3 for a ratio α = -0.5. Increasing p makes the first order region to shrink. On the other hand increasing α enlarges it. We present a new probabilistic mean field treament which yields the correct qualitative features of the phase diagram.