Phase Transitions in the Modified Weiss Model

摘要

In a recent paper, the modified model by P Weiss was applied to ferroelectrics. Typical ferroelectric properties could be simulated. A further generalization of the Weiss model is the assumption of a power law feedback with an exponent K between the polarization of the permanent dipoles and the local field. The Weiss model is included for the xponent K = 1 and we obtain a second-order type phase transition. For values K > I the simulations yield first-order type phase transitions whereas we obtain diffusive-type phase transitions for values K < 1.