Figure 7.

Experimental (main panels) and simulated (insets) STM images of the Ti-modified (1 × 1) surface of Fe₂O₃(11̅02). At negative sample bias (a), the surface reconstruction appears as a missing zigzag row of O atoms in the topmost layer along the [11̅01̅] direction. At positive sample bias (b), two Fe rows are missing from the top cation layer and are imaged as a dark area surrounded on both sides by isolated point features. The experimental STM images qualitatively match with those simulated assuming the trench defect model. The STM simulations were performed at a constant height (3 Å above the surface) on a (6 × 1) supercell, with U_sample = −2 and +2 V in (a) and (b), respectively. The STM images are 9 × 9 nm².