Surface spin slips in thin dysprosium films

We report a theoretical investigation of new magnetic phases of thin dysprosium films. At the surfaces, the balance between exchange and anisotropy energies favors the alignment of spins along the basal plane easy axis directions. Near the Curie temperature, the helimagnetic phase is strongly modified, allowing surface spins to lock into the basal plane anisotropy easy directions. As the temperature raises, we find transitions to other surface lockin patterns, which are tunable by external field strengths of a few hundred milli-Oersteds.