Figure 3.

(a) SEM image of the heterostructural SrTiO₃/Bi₄Ti₃O₁₂ platelet with the core-rim structure after 1 h of the TC reaction at 200 °C (Sr/Ti = 12, 6 M NaOH). (b) STEM and (c) EDS analyses revealing the distribution of Bi, Ti, Sr, and O in the heterostructural platelet. (d) Close-up look with the focus set on the SrTiO₃ surface layer from the marked area of the platelet in the inset. (e) Magnified region around the core-rim contact showing the decomposition of Bi₄Ti₃O₁₂. (f) Higher magnification of the marked area in (e) and a fast Fourier transform (FFT) pattern in the inset.