Fig. 2: Structural and compositional characterization of the Bi0.4Sb1.6Te3 pellet.
a X-ray diffraction (XRD) pattern matching PDF #01-072-1836, confirming the absence of secondary phases. b Secondary electron (SE) and Backscattered electron (BSE) images highlighting compositional contrast, with Bi-rich domains appearing bright and Sb-rich domains dark. c BSE image of a selected region from (b) with corresponding energy-dispersive X-ray spectroscopy (EDS) maps for Bi, Sb, and Te distribution. d EDS line scan along the selected region in (c), showing compositional variation between Bi-rich and Sb-rich domains. e Representative EDS spectra from Bi-rich and Sb-rich domains in (c), with tables giving the elemental contents shown as insets. f Statistic summary of average atomic percentages of Bi and Sb in Bi-rich and Sb-rich domains.
