Statics and dynamics of domain walls in bubble materials

Abstract

The wall structure of planar domain walls in magnetic thin films of perpendicular anisotropy is calculated starting from a differential equation somewhat generalized from the one first introduced by Slonczewski. Solving this differential equation both for static and for stationary moving walls by a finite-difference method yields as results the wall profiles, the effective masses, the energies, and the critical velocities for ordinary walls as well as for Bloch line carrying, so-called heavy, walls. The critical velocities which were obtained are generally smaller than previously assumed. One conclusion drawn from the character of the instabilities at the critical velocities is that there will be no dynamically induced stacking of horizontal Bloch lines for films in the thickness range preferred for bubble applications.