The high confidence of the values measured allowed quantification of gradients. We first compared values around 0.25 and 2.0 μm, D(Elemental Ratio)core-edge in Table , where values were reasonably stable and not subject to oscillations. The decrease in Ni ratio was 0.14/0.13 for 63%Ni (Table , Particle 1/Particle 2), while greater decreases of 0.21/0.17 and 0.18/0.19 were observed for 80%Ni and 86%Ni, respectively.