The electronic structures of a (001) surface of crystalline Dy2Fe14B and Nd2Fe14B have been studied and the crystal field parameters at the rare-earth sites have been estimated by using first principles calculations. It is shown that Dy or Nd ions at the surface exhibit an in-plane magnetic anisotropy and can be nucleation sites of magnetization reversal.

No abstract

We theoretically analyzed a magnetic wall confined in a nano-contact spin valve paying special attention to the penetration of the magnetic wall into thin ferromagnetic electrodes. We showed that, compared with the Bloch wall, the penetration of the Néel wall is suppressed by increases of the demagnetization energy. We found the optimal conditions of the radius and height of the nano-contact to maximize the power of the current-induced oscillation of the magnetic wall. We also found that the thermal stability of the Bloch wall increases when the nano-contact's radius increases or height decreases.