Fig. 6: Electronic heterogeneity of the NiO superlattice.
From: Initial atomic-scale oxidation pathways on a Ni–15Cr(100) alloy surface
Panel (a) is the topography image of the NiO–NiCr(100) superlattice structure and (b) the corresponding normalized dI/dV map (proportional to LDOS) at Vslice = −2.7 V. The image inset in (a) shows the orientation of the next NiO layer and is from a Ni–12 wt%Cr(100) sample shown here for comparison (image size 20 × 20 nm2). The white arrows point to small protrusions in the NiO positioned over the groove site of the superlattice. The red and black dots in the LDOS map represent the superlattice top site and the groove site, respectively, where the average, normalized dI/dV spectra shown in (c) were acquired. The inset above the normalized spectra shows the difference in the differential conductance of the respective sites. Panel (d) is a distribution of the band gap values extracted from the entire LDOS map shown in (b). Imaging conditions: (a) Vbias = 2.0 V, It = 0.1 nA, and the inset at Vbias = −1.0 V, It = 0.1 nA. The scale bar is 10 nm. The error bars in (c) were calculated using standard error.
