Abstract
We report collective ferromagnetic behavior with high Curie temperatures () in Fe dot assemblies supported by the Cu(111) surface. Our ability to tune the average size and spacing of the individual dots allows us to conclude that enhanced magnetic anisotropy cannot account for this high- ferromagnetic order. Because our Monte Carlo simulations have ruled out the dipolar interaction as the dominant factor in this system, we attribute the origin of the ferromagnetic order to indirect exchange coupling via the Cu(111) substrate.
- Received 23 February 2004
DOI:https://doi.org/10.1103/PhysRevLett.92.237201
©2004 American Physical Society