Figure 7
A comparison of (a) a high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) image with (b) bulk and (c) interfacial species maps of sample 1A, taken from the rim of the pellet. Each pixel of the stack was fitted as a linear combination of the NMF component spectra. Red lines on the species maps are a guide for the eye to indicate the position of the intergranular crack. Note the difference in the maxima of the intensity scale bars on the right-hand side. The STXM pixel size is 50 nm × 50 nm and the HAADF-STEM image is scaled to match the STXM images. |