Fig. 4: Local electric field and defect configuration of ceramics.
a Topographies, and (b) surface potential mapping of BCTZ–1.75AlN–300 ceramics measured using KPFM. c Surface potential profiles along the long edge of the region defined by the blue dashed box, as derived from the surface potential mappings. Inset is the schematic diagram of the KPFM testing. d XPS spectra of O1s in BCTZ and BCTZ–1.75AlN–300 ceramics. e The concentration of oxygen vacancies (O2/O1 ratios). f Impedance spectra of BCTZ, BCTZ–xAlN–300 ceramics at 500 °C. g Fitted Ea values of grains and grain boundaries in BCTZ–xAlN–300 ceramics.
