|Título||Ising nematic phase in ultrathin magnetic films : a Monte Carlo study
Cannas, Sergio A.
Michelon, Mateus Fontana
Stariolo, Daniel Adrian
Tamarit, Francisco A.
|Abstract||We study the critical properties of a two-dimensional Ising model with competing ferromagnetic exchange and dipolar interactions, which models an ultrathin magnetic film with high out-of-plane anisotropy in the monolayer limit. We present numerical evidence showing that two different scenarios appear in the model for different values of the exchange to dipolar intensities ratio, namely, a single first-order stripe-tetragonal phase transition or two phase transitions at different temperatures with an intermediate Ising nematic phase between the stripe and the tetragonal ones. Our results are very similar to those predicted by Abanov et al. Phys. Rev. B 51, 1023 1995 , but suggest a much more complex critical behavior than predicted by those authors for both the stripe-nematic and the nematic-tetragonal phase transitions. We also show that the presence of diverging free energy barriers at the stripe-nematic transition makes possible to obtain by slow cooling a metastable supercooled nematic state down to temperatures well below the transition one.
|Contido em||Physical review. B, Condensed matter and materials physics. Woodbury. Vol. 73, no. 18 (May 2006), 184425 12p.
Interações de troca (elétron)
Modelo de ising
Simulação de Monte Carlo
|Tipo||Artigo de periódico
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