NONEQUILIBRIUM PHASE-TRANSITIONS IN ONE-DIMENSIONAL KINETIC ISING-MODELS

A family of non-equilibrium kinetic Ising models, introduced earlier, evolving under the competing effect of spin Rips at zero temperature and nearest-neighbour random spin exchanges, is further investigated. By increasing the range of spin exchanges and/or their strength the nature of the phase transition 'Ising-to-active' becomes of (dynamic) mean-field type and a first-order tricitical point is located at the Glauber (delta = 0) limit. Corrections to the mean-field theory are evaluated up to sixth order in a cluster approximation and found to give good results concerning the phase boundary and the critical exponent beta of the order parameter which is obtained as beta similar or equal to 1.0.