EXCHANGE FORCE IMAGE OF MAGNETIC SURFACES — A First-Principles Study on NiO(001) Surface —

摘要

A recently proposed surface atom-probe technique, exchange force microscopy, is examined on an antiferromagnetic NiO (001) surface system. It is shown that atomic force of a ferromagnetic Fe probe on the surface gives a clear spin image when the probe is located within 1A above the contact point. Exchange force images show antiferromagnetic pattern of the Ni sites along the [110] direction and asymmetry around the O sites. The asymmetric feature comes from the superexchange interaction between the probe and the second-layer Ni atoms via the surface O ion, being a key proof of the exchange force image on observation.