Ordering and phase transitions in randomfield Ising systems
Abstract
An exact analysis of the Ising model with infiniterange interactions in a random field and a local meanfield theory in three dimensions is carried out leading to a phase diagram with several coexistence surfaces and lines of critical points. Our results show that the phase diagram depends crucially on whether the distribution of random fields is symmetric or not. Thus, Isinglike phase transitions in a porous medium (the asymmetric case) are in a different universality class from the conventional randomfield model (symmetric case).
 Publication:

Physical Review Letters
 Pub Date:
 September 1991
 DOI:
 10.1103/PhysRevLett.67.1821
 Bibcode:
 1991PhRvL..67.1821M
 Keywords:

 Antiferromagnetism;
 Binary Mixtures;
 Hamiltonian Functions;
 Ising Model;
 Phase Diagrams;
 Phase Transformations;
 Cubic Lattices;
 Ferromagnetism;
 Porous Materials;
 Random Processes;
 Thermodynamics and Statistical Physics;
 05.50.+q;
 64.70.Fx;
 75.10.Hk;
 Lattice theory and statistics;
 Liquidvapor transitions;
 Classical spin models