Order-Disorder Transitions in the Ising Model

The approach considered, that allows research a processes of order-disorder transition in various systems (with any distribution of the exchange integrals signs) in the Ising model. A new order parameters, that can give description of a phase transitions, is found. These parameters are defined as the mean value of percolation cluster size. Percolation cluster includes spins with given energy. The transition from absolute disorder into correlated phase could be studied with using of percolation theory methods. Transitions paramagnetic-superparamagnetic, paramagnetic-spin glass and paramagnetic-clustered antiferromagnetic are considered.