Low-temperature sintering of Li2CO3/CuO co-added Ce-doped lead-free BNKBT ceramics and their multilayer capacitor applications

In this study, 0.75 wt% Li2CO3/CuO sintering aids co-added, 1.0 mol% Ce-doped lead-free piezoelectric 0.854(Bi0.5Na0.5TiO3)–0.12(Bi0.5K0.5TiO3)–0.026(BaTiO3) (BNKBT) ceramics were prepared by the solid-state reaction method, and the optimum sintering temperature decreased from 1150 to 950℃ with liquid phase sintering. The structural and electrical properties of Li2CO3/CuO co-added 1.0 mol% Ce-doped BNKBT ceramics, sintered at a low temperature of 950℃, were investigated in detail. The Curie temperature has been shifted to lower temperatures with decreasing sintering temperature. When sintered at 950℃ for 2 h, the releasable energy density of 1.0 mol% Ce-doped BNKBT ceramic was calculated as 0.287 J/cm3 at 60 kV/cm, which is comparable to the value obtained at a sintering temperature of 1050℃. Promising results were achieved at low sintering temperatures for Li2CO3/CuO co-added 1.0 mol% Ce-doped ceramics, indicating a potential for multilayer ceramic capacitor (MLCC) applications. The capacitance and dielectric loss tangent values of BNKBT-MLCC, measured at room temperature and 1 kHz, are 16.7 nF and 0.068, respectively.