fig2

Figure 2. The microstructure of BTO/STO-BFO SPE film on (111)-STO substrate. (A) The XRD of BTO, BTO/STO SLs and BTO/STO-BFO SPE films; (B-D) The RSM of (B) BTO, (C) BTO/STO SLs and (D) BTO/STO-BFO SPE films around the (222) reflections; (E) The STEM image and EDS of the BTO/STO-BFO SPE film; (F) The STEM image of BTO/STO SLs with the corresponding EDS element mapping; (G) The high-resolution STEM image of BTO/STO-BFO SPE film with the corresponding EDS element mapping. BTO: Barium titanate; STO: strontium titanate; BFO: bismuth ferrite; SLs: superlattices; SPE: superparaelectric; XRD: X-ray diffraction; RSM: reciprocal space mapping; STEM: scanning transmission electron microscopy; EDS: energy-dispersive X-ray spectroscopy.