Dispersion of magnetic anisotropy in size-selected CoPt clusters

The magnetic anisotropy energy distribution of a diluted assembly of CoPt nanoparticles, size-selected around a diameter of 3 nm, is characterized by superconducting quantum interference device magnetometry. By comparison with unselected CoPt clusters and size-selected Co clusters, we show experimental evidence of a significant anisotropy constant dispersion, which is a nanoalloy specificity.