fig9

Figure 9. Dopant-graded strategy to enhance temperature stability. (A) Schematic diagram illustrating the temperature-dependent piezoelectricity of KNN ceramics. (B) Schematic diagram of composition grading with diffuse PPT. (C) SEM image of the DGC with a multilayer structure. (D) Dielectric-temperature curves of the DGC and each individual layer. (E) Calculated γ using the modified Curie-Weiss law. (F and G) Temperature dependence of d₃₃ for the DGC and each individual layer. This figure quoted with permission^[31]. Copyright 2022, Wiley-VCH.