Effect of surface roughness on magnetic domain wall thickness, domain size, and coercivity

We study the effect of surface roughness on magnetic domain wall thickness, domain size, and coercivity of thin magnetic films. We show that the rough ness increases (decreases) the domain wall thickness and domain size for Bl och walls (Neel walls). The surface roughness affects the domain wall movem ent and causes the increase of coercivity for Neel walls. The coercivity du e to domain rotation for Bloch walls decreases with the increase of roughne ss. The domain wall thickness, domain size, and coercivity are each related to the demagnetizing factor, which depends on the roughness and type of wa ll (Bloch wall or Neel wall). The calculated coercivity versus thickness is compared with experimental data of ultrathin Co films, where the thickness dependent roughness parameters are available. (C) 2001 American Institute of Physics.