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Phase diagram of the three‐dimensional anisotropic Heisenberg anti‐ferromagnetic model
Author(s) -
Rocha J. C. S.,
Costa B. V.
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200844461
Subject(s) - phase diagram , ising model , condensed matter physics , critical exponent , heisenberg model , physics , phase transition , monte carlo method , ferromagnetism , paramagnetism , anisotropy , scaling , critical line , renormalization group , statistical physics , phase (matter) , quantum mechanics , mathematics , geometry , statistics
Abstract In this work we use numerical Monte Carlo techniques to study the phase diagram of the three‐dimensional classical Heisenberg anti‐ferromagnetic (AF) model with single‐ion anisotropy model with an uniform magnetic field applied along the easy axis. Early experimental as well as theoretical calculations have shown that the phase diagram of the model is quite rich. We simulated the model on a simple cubic lattices using the Wang–Landau sampling and Metropolis algorithm. Finite size scaling theory is used to obtain the phase diagram. At low field and low temperature the system exhibits AF order separated from a spin‐flop (SF) phase by a first‐order line. As temperature grows a paramagnetic phase is reached by crossing a second‐order line both from the AF phase and from the SF phase. The critical exponents are obtained for each transition line. Contrary to early works we find that the line separating the SF phase from the paramagnetic phase is in the Ising class of universality.