Magnetism, structure and chemical order in small CoPd clusters: A first-principles study

•This work analyses the structural and magnetic properties of CoPd nanoclusters.•The magnetic order is found to be ferromagnetic-like for all the ground-state structures.•The average magnetic moment per atom increases approximately linearly with Co content.•The influence of spin–orbit interactions on the cluster properties is discussed.

The structural, electronic and magnetic properties of small ComPdnComPdn(N=m+n=8,m=0−N)(N=m+n=8,m=0−N) nanoalloy clusters are studied in the framework of a generalized-gradient approximation to density-functional theory. The optimized cluster structures have a clear tendency to maximize the number of nearest-neighbor CoCo pairs. The magnetic order is found to be ferromagnetic-like (FM) for all the ground-state structures. Antiferromagnetic-like spin arrangements were found in some low-lying isomers. The average magnetic moment per atom μ¯N increases approximately linearly with Co content. A remarkable enhancement of the local Co moments is observed as a result of Pd doping. This is a consequence of the increase in the number of Co d holes, due to CoPd charge transfer, combined with the reduced local coordination. The influence of spin–orbit interactions on the cluster properties is also discussed.