Figure 3

Crystal structures of Sr-Ti-O thin films deposited onto a Nb-doped SrTiO3 (001) single crystal (part-2). (a) HRTEM image at the interface between the thin film and the Nb-SrTiO3 substrate for the sample presented in Figure 2d. (b) Change of lattice expansion (Δc) with composition. The Δc was calculated as the difference between the out-of-plane lattice parameter of the thin films from that of bulk SrTiO3. The changes of Δc estimated by Ohnishi et al.25 for Ruddlesden-Popper (SrTiO3)x-SrO phases when treated as pseudocubic cells are also shown. (c) Reciprocal space map around SrTiO3 (103) for the film presented in Figure 2b. (d) Schematic drawing of spontaneously formed superlattice structure.