Fig. 4: Real-space image of the PtO3–Pt structure.

a,b, STM images of the clean Pt(111) surface (a) and the fully covered PtO3–Pt layer (b). The insets in a and b are the corresponding LEED patterns. c, Atomic-resolution STM images of the PtO3–Pt layer. d, Simulated STM image of the PtO3–Pt layer based on the structure shown in Fig. 3j. e,f, Enlarged image of the white box in c (e) and d (f). g, The top and bottom panels show the enlarged image of the black box in c and d, respectively; the line profile is a comparison between the experimental (along the green line in g(i)) and theoretical (along the blue line in g(ii)) results; the middle panel is the electron density isosurface map from the top and side views. The LEED patterns were collected under the same energy (48 eV) and followed the same direction. Size and tunnelling parameters: (a) 500 nm × 500 nm, Vs = 50 mV, I = 1 nA; (b) 100 nm × 100 nm, Vs = 1.74 V, I = 0.07 nA; (c) 9.5 nm × 9.5 nm, Vs = 1.06 V, I = 0.07 nA.