Laser-assisted atom probe tomography investigation of magnetic FePt nanoclusters: First experiments

FePt nanoclusters dispersed in a Cr matrix have been investigated by laser-assisted atom probe tomography. The results were analysed according to simulated evaporation experiments. Three–dimensional (3D) reconstructions reveal the presence of nanoclusters roughly spherical in shape, with a size in good agreement with previous transmission electron microscopy observations. Some clusters appear to be broken up after the evaporation process due to the fact that the Cr matrix has a lower evaporation field than Fe and Pt. It is thus shown that the observed FePt nanoclusters are chemically homogeneous. They contain Fe and Pt in equiatomic proportions, with no core–shell structure observed.

► FePt nanoclusters dispersed in a Cr matrix were studied by atom probe tomography.
► Simulated experiments were conducted to study the artefacts of the analysis.
► In FePt nanoclusters, Fe and Pt are present in equiatomic proportions.
► FePt nanoclusters are homogeneous, no core–shell structure is observed.