Quantifying the composition of yttrium and oxygen rich nanoparticles in oxide dispersion strengthened steels

► First APT analysis of bulk Y2O3 oxide. ► Comparison with the composition of YO based nanoclusters in ODS steel. ► Sequence of ion hits on the detector show that there is a bias towards Y loss. ► Nanoparticles are concluded to have a ∼1:1 Y:O ratio.