ON THE INFLUENCE OF MICROSCOPIC DYNAMICS IN NONEQUILIBRIUM STATIONARYSTATES - A MEAN-FIELD EXAMPLE

We discuss the role of the microscopic stochastic dynamics in the macr oscopic properties of a simple spin-flip non-equilibrium mean field mo del where ferromagnetic and antiferromagnetic interactions are competi ng. We have found that different analytical forms for the dynamic mech anism give rise to different stationary states at low temperature, in contrast to what happens at equilibrium. We also find an effective fre e-energy functional which allows us to classify the stable and metasta ble stationary solutions.