Since the mass of the material notably decreased outside of the range between 0.25 and 2.0 μm from the particle surface (Figure ), smaller sampling sizes existed at those distances. Going back to Figure , beyond 2.0 μm, the lower sampling sizes induced by particle voids significantly widened the intervals of composition at 99% confidence, making the assessment of gradients unreliable. However, these intervals remained rather narrow between 0 and 0.25 μm. It is intriguing that compositional gradients were apparent at such narrow spatial distances. Specifically, there was a systematic trend for Mn enrichment at the expense of Co in all three samples. The Ni ratio remained comparably stable in 63%Ni and 80%Ni, but there was a visible enrichment in 86%Ni, further adding to the spatial variability of composition for this latter material. Further exploration of variations at such short distances demands techniques with higher spatial resolution, like transmission electron microscopy.