Relaxation of labyrinth domain structure of ferromagnetic thin film under field cycles

The relaxation of a two-dimensional labyrinth pattern of magnetic domain st ructure in a uniaxial garnet thin film is studied. The usually observed dom ains of the labyrinth structure contain many defects. The labyrinth structu re changes to a parallel-stripe structure under magnetic field cycles. In t his 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 do mains 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 junct ions decreases with the power law as a function of the number of ac magneti c field cycles.