Construction of an approximate solution for an Ising magnet in an external magnetic field

A method of approximate calculation the magnetization an Ising magnet located in external magnetic field is proposed. This based on using exact or expression for spontaneous same lattice. The uses ratio effective fields clusters one and two lattice nodes. Using proposed a field, dependence temperature magnitude calculated. applied work to solution mean approximation, Beta approximation square lattice; all these solutions, critical indices characterizing behavior are Keywords: model, phase transitions, influence field.