fig2

Figure 2. Characterization of PTO(Ni) film on NSTO substrate. (A) SEM image of PTO(Ni) film; (B) Cross-sectional HAADF-STEM image of PTO(Ni) film; (C) Atomic-scale cross-sectional HAADF-STEM image of PTO(Ni)/NSTO interface; (D) TOF-SIMS spectra of PTO(Ni) film; (E) Ti L_2,3 spectra perpendicular to the interface corresponding to the boxes in (B); (F) Out-of-plane PFM phase image of PTO(Ni) film. PTO: PbTiO₃; NSTO: Nb:SrTiO₃; SEM: scanning electron microscope; HAADF-STEM: high-angle annular dark-field scanning transmission electron microscopy; TOF-SIMS: time-of-flight secondary-ion mass spectrometry; PFM: piezoelectric force microscope.