Figure 3

(a) Dendrogram obtained from HCA of the first 5 PCs of SEM–EDX SPDCs of NU-A sample. Comparison of spatial distribution for EDX of (b) potassium (K), bromide (Br), and aluminium (Al), and (c) Al spatial distribution detected by the three elemental techniques with the KBr mask being applied to EDX data (white areas). Common analysis area is marked with a white square. Scale bars correspond to 100 μm.