First-principles calculation of exchange force on a magnetic Fe surface

We have investigated the exchange force between two Fe 001. films by first-principles calculations to show the feasibility of exchange force microscopy which probes the exchange force between a tip and a sample. We found that a surface magnetic image of an Fe 001.surface with atomic resolution can be achieved by measuring the exchange force. The image contrast was clearly enhanced when dra-1, where d is the distance between the two films and a is the lattice constant of bulk Fe. q1999 Elsevier Science B.V. All rights reserved