We demonstrate the occurrence of compensated spin configurations in Fe clusters and monolayers on Ru(0001) and Rh(111) by a combination of X-ray magnetic circular dichroism experiments and first-principles calculations. Our results reveal complex intra-cluster exchange interactions which depend strongly on the substrate 4d-band filling, the cluster geometry as well as lateral and vertical structural relaxations. The importance of substrate 4d-band filling manifests itself also in small nearest-neighbor exchange interactions in Fe dimers and in an nearly inverted trend of the Ruderman-Kittel-Kasuya-Yosida coupling constants for Fe adatoms on the Ru and Rh surface.
@article{arxiv.1403.4188,
title = {Complex trend of magnetic order in Fe clusters on 4$d$ transition-metal surfaces},
author = {V. Sessi and F. Otte and S. Krotzky and C. Tieg and M. Wasniowska and P. Ferriani and S. Heinze and J. Honolka and K. Kern},
journal= {arXiv preprint arXiv:1403.4188},
year = {2014}
}