fig18

Figure 18. Core-shell powder design and multiscale optimization in lead-free RFE ceramics. (A) Schematic of core-shell powder architecture for (Na_0.5Bi_0.5TiO₃@La₂O₃)-(SrSn_0.2Ti_0.8O₃@La₂O₃)-Bi₂O₃-B₂O₃-SiO₂ system and the corresponding sintered composite ceramics. This figure is quoted with permission from Zhang et al.^[146]; (B) Multiscale synergistic optimization in Na_0.4K_0.1Bi_0.5TiO₃@(SrZrO₃-BiMg_0.5Sn_0.5O₃)@SiO₂ composite ceramics, featuring pre-synthesized core-shell powders and bright-field TEM imaging. This figure is quoted with permission from Zhang et al.^[147]. TEM: Transmission electron microscopy; NBT: Na_0.5Bi_0.5TiO₃; SST: SrSn_0.2Ti_0.8O₃; NKBT: Na_0.4K_0.1Bi_0.5TiO₃; SZ-BMS: SrZrO₃-BiMg_0.5Sn_0.5O₃; BDS: breakdown strength; NWS: Maxwell-Wagner-Sillars; SST: SrSn_0.2Ti_0.8O₃.