Metastable and nonuniform states in 2D orthorhombic dipole system

The energy of a system of 3D dipoles on a 2D orthorhombic lattice is investigated as a function of the rhombic angle. The possibility of the metastable ferromagnetic state above the main antiferromagnetic state is shown. The mechanisms of magnetization reversal are analyzed. Nonuniform structures with the long range order of the ferromagnetic type (vortices and domain walls) on bounded lattices are considered. The conditions when the upper terms of the long wave expansion of the Fourier images of the dipole sums plays a significant role ape shown. (C) 1999 Elsevier Science B.V. All rights reserved.