Figure 2

HAADF STEM image of the Fe₃O₄ film and SrTiO₃ substrate viewed along the [−110] and [1−10]zone axis, respectively. Overlaid structural models identify the magnetite and SrTiO₃ atomic columns; octahedral (Fe_B) and tetrahedral (Fe_A) atomic columns are shown in red and yellow, respectively; Sr-O with purple while Ti atomic columns with green dots. Atomic columns of O are not shown due to negligible intensity compared to those of Sr, Ti and Fe. Region between the white and yellow dashed lines represents the interface region in which two distinctive atomic columns (labelled as ‘a’ and ‘b’) are identified, as shown in the magnified image (from the area enclosed with the dashed white rectangle) given as inset.