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arXiv · 1004.2065

Nonequilibrium phase transitions and tricriticality in a three-dimensional lattice system with random-field competing kinetics

Nuno Crokidakis
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Abstract

We study a nonequilibrium Ising model that stochastically evolves under the simultaneous operation of several spin-flip mechanisms. In other words, the local magnetic fields change sign randomly with time due to competing kinetics. This dynamics models a fast and random diffusion of disorder that takes place in dilute metallic alloys when magnetic ions diffuse. We performe Monte Carlo simulations on cubic lattices up to L=60. The system exhibits ferromagnetic and paramagnetic steady states. Our results predict first-order transitions at low temperatures and large disorder strengths, which correspond to the existence of a nonequilibrium tricritical point at finite temperature. By means of standard finite-size scaling equations, we estimate the critical exponents in the low-field region, for which our simulations uphold continuous phase transitions.

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BibTeXRIS

Nuno Crokidakis. 2010-04-12. Nonequilibrium phase transitions and tricriticality in a three-dimensional lattice system with random-field competing kinetics. https://doi.org/10.1103/physreve.81.041138

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