Figure 1: SEM and TEM-EDXS characterization of franckeite.
From: Exfoliation of natural van der Waals heterostructures to a single unit cell thickness
(a–c) SEM images of franckeite immobilized on a conductive carbon support. Zoom areas are highlighted by the magenta rectangles. The scale bars denote 5 μm. (d–h) TEM-EDXS maps of a franckeite crystal showing lead, tin, antimony, iron and sulphur, respectively. The scale bars denote 30 nm. (i) Averaged EDXS spectra with the inset showing the low-intensity peaks at low energies. The peaks of the five major elements used for the quantification shown in Table 1 are marked in red. The secondary peaks and the peaks originating from the substrate and impurities, which were de-convoluted and excluded from the quantification, are marked in black.
