Fig. 2

A compilation of all µ-XAS spectra. Normalized Ni K-edge µ-XANES spectra, 13 total (a); a close-up view of the first large oscillation close to the end of the XANES region (b); Ni K-edge µ-EXAFS spectra, 8 total (c). The spectra are shown in order of appearance in Additional file 1 and progress numerically and alphabetically with respect to sample name and regions of interest. All spectra are color coded to remain the same throughout the manuscript and Additional file 1