Figure 2

LEED analysis and illustration of the surface reconstruction.
LEED pattern of (a) TiO2 terminated STO substrate and (b) 1.5 u.c. Sr rich STO thin film. The colors are reversed to intensify the contrast. The green arrows are for the ((√13 × √13)-R33.7°) and the red arrows are for the (2 × 2) reconstructions, respectively. The blue arrows are for (1 × 1) diffraction spots. (c,d) Model for possible surface reconstructions on substrate and Sr rich STO surfaces.