MAGNETIC REVERSAL ON VICINAL SURFACES

We present ii theoretical study of in-plane magnetization reversal for vicinal ultrathin films using a one-dimensional micromagnetic model w ith nearest-neighbor exchange, fourfold anisotropy at all sites, and t wo-fold anisotropy at step edges. A detailed ''phase diagram'' is pres ented that catalogs the possible shapes of hysteresis loops and revers al mechanisms as a function of step anisotropy strength and vicinal te rrace length. The steps generically nucleate magnetization reversal an d pin the motion of domain walls. No sharp transition separates the ca ses of reversal by coherent rotation and reversal by depinning of a 90 degrees domain wall from the steps. Comparison to experiment is made when appropriate. [S0163-1829(98)08338-6].