Complex trend of magnetic order in Fe clusters on 4d transition-metal surfaces. I. Experimental evidence and Monte Carlo simulations

Sessi, V.Otte, F.Krotzky, S.Tieg, C.Wasniowska, M.Ferriani, P.Heinze, S.Honolka, J.Kern, K.2014-06-232014-06-232014-06-23201410.1103/PhysRevB.89.205425https://infoscience.epfl.ch/handle/20.500.14299/104590WOS:000336248300005We 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, first-principles calculations, and Monte Carlo simulations. Our results reveal complex intracluster 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 a nearly inverted trend of the Ruderman-Kittel-Kasuya-Yosida coupling constants for Fe adatoms on the Ru and Rh surface.Complex trend of magnetic order in Fe clusters on 4d transition-metal surfaces. I. Experimental evidence and Monte Carlo simulationstext::journal::journal article::research article