Phase transitions in lattices of magnetic dipoles

Hexagonal magnetic-dipole lattices containing three to six rows are investigated. Conditions of the excitation of phase transitions that change the orientation configuration of the system are revealed on the basis of a numerical analysis. The changes in the magnetic moment of the system and in the energy of dipole-dipole interaction upon the emergence of phase transitions are found. Both symmetric phase transitions propagating identically on the two sides of the lattice away from the excitation region and asymmetric phase transitions such in which the configurations of the system to the left and to the right of the excitation region are different are considered. Conditions under which there occur unidirectional phase transitions in which either the left-or the right-hand front of the phase transition propagates along the lattice are found.