Fig. 3: Crystal structures and electronic structures analysis.

a XRD patterns. b Synchrotron 2D-XRD patterns of the Sn–Bi bimetallic interface. c–e XANES spectra of Bi L₃-edge, Sn K-edge and Sn L₃-edge. f XPS spectra of Sn 3d spectrum and Bi 4 f spectrum for Sn–Bi interface and alloy. Solid color lines represent the curve fittings.