| Numéro |
J. Phys. Colloques
Volume 49, Numéro C8, Décembre 1988
Proceedings of the International Conference on Magnetism
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|
|---|---|---|
| Page(s) | C8-2053 - C8-2054 | |
| DOI | https://doi.org/10.1051/jphyscol:19888930 | |
Proceedings of the International Conference on Magnetism
J. Phys. Colloques 49 (1988) C8-2053-C8-2054
DOI: 10.1051/jphyscol:19888930
1 Low Temperature Laboratory, Helsinki University of Technology, SF-02150 Espoo, Finland
2 The Technical University of Denmark, Bldg. 307, DK-2800 Lyngby, Denmark
3 Risø National Laboratory, DK-4000 Roskilde, Denmark
J. Phys. Colloques 49 (1988) C8-2053-C8-2054
DOI: 10.1051/jphyscol:19888930
COMPUTER SIMULATION AND MEAN FIELD CALCULATION OF PHASE DIAGRAM AND ADIABATIC DEMAGNETIZATION PATHS FOR AN ANTIFERROMAGNET
H. E. Viertiö1, O. G. Mouritsen2 et P.-A. Lindgård31 Low Temperature Laboratory, Helsinki University of Technology, SF-02150 Espoo, Finland
2 The Technical University of Denmark, Bldg. 307, DK-2800 Lyngby, Denmark
3 Risø National Laboratory, DK-4000 Roskilde, Denmark
Abstract
A Monte Carlo simulation of a two-dimensional nuclear antiferromagnet is presented and compared with mean field calculations. The model includes nearest neighbor dipolar and exchange interactions and a single ion term. The phase diagram as a function of field and temperature is calculated, and the constant entropy lines, which are the paths of adiabatic nuclear cooling, are included. The fluctuations reduce the transition temperatures strongly, whereas the isentrops are altered much less relative to those calculated by the mean field theory. The dynamics of the ordering process after "quenches" is studied under constant field, temperature, and entropy conditions.