In this paper we apply the Landau-Ginzburg model to a uniaxial ferromagnet including the possibility of magnetic inhomogeneities in the sample. The effects of external magnetic fields on the various homogeneous and inhomogeneous magnetic structures that minimize the free energy are studied. Using exact methods of nonlinear analysis, space-dependent solutions of the equation of state are found, and their mean magnetizations are calculated. A combination of analytical and numerical methods is then employed in the study of their energies. Finally, the role of various magnetization patterns is investigated in the Arrott plots for magnetization processes.

• Received 27 June 1991

DOI:https://doi.org/10.1103/PhysRevB.44.10040