Relaxation of Labyrinth Domain Structure of Ferromagnetic Thin Film under Field Cycles

Abstract

The relaxation of a two-dimensional labyrinth pattern of magnetic domain structure in a uniaxial garnet thin film is studied. The usually observed domains of the labyrinth structure contain many defects. The labyrinth structure changes to a parallel-stripe structure under magnetic field cycles. In this evolution, defects of the domain pattern disappear. We have introduced a number of magnetic domain junctions as characteristic values of a domain pattern. A magnetic domain junction is defined as a point where magnetic domains in the same direction intersect like a three-forked road. This is one type of defect in the domain pattern. It is found that the number of junctions decreases with the power law as a function of the number of ac magnetic field cycles.