Stability of one dimensional steady state domain wall motion

The magnetization configuration and stability limits of one-dimensional domain walls with orthorhombic anisotropy and an applied field normal to the wall are studied in steady-state motion. The calculations are carried out directly on the directional sphere in the lossless instance. The Walker breakdown mechanism, in which the motion breaks down simultaneously along the entire wall profile, is replaced by three distinct mechanisms: domain instability in which the wall motion breaks down asymptotically far from the center of the wall, and two types of domain-wall instability in which the breakdown occurs within the wall. The two types of domain-wall instability are distinct in that only one is identified by Jacobi equation analysis