Mass-filtered ferromagnetic alloy clusters on surfaces

Mass filtered FeCo clusters with diameters in the order of magnitude of 12 nm were prepared in a new developed, continuously working cluster source and deposited on a Si surface. The AFM measurements exhibit a height being smaller than the diameter for free particles which can be explained by particle–support interaction. Larger clusters are due to the mass selecting process in an electrostatic quadrupole which separates with different m/e ratios. Magnetic properties were determined by X-ray magnetic circular dichroism (XMCD) with elemental specification.