Coercivity of domain-wall motion in thin films of amorphous rare-earth-transition-metal alloys

Computer simulations of a two-dimensional lattice of magnetic dipoles are performed on the Connection Machine. The lattice is a discrete model for thin films of amorphous rare-earth-transition-metal alloys with application to erasable optical data-storage systems. Simulated dipoles follow the dynamic equation of Landau, Lifshitz, and Gilbert under the influence of an effective magnetic field arising from local anisotropy, near-neighbor exchange, classical dipole-dipole interactions, and externally applied fields. By introducing several types of defects and inhomogeneities in the lattice, we show that the motion of domain walls can be hampered in various ways and to varying degrees.