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Description
Magnetization curves recorded with X-ray magnetic circular dichroism on samples with a few % of a monolayer (ML) of Dy atoms on highly oriented pyrolytic graphite (HOPG) indicate two distinct magnetic species with mutual antiferromagnetic interactions. To understand the origin and magnetic interactions of the species, spatial distributions of Dy atoms and small clusters were studied using scanning tunneling microscopy. While deposition at 10K gave statistical growth, deposition at 40–60K with possible thermal diffusion led to equally spaced atoms suggesting repulsive dipolar interactions caused by charge transfer between the adatom and substrate. The atoms have a direct capture area of a 3-sites radius; atoms landing inside that area form dimers.
