Dielectric properties and reliability of calcium-doped BaTiO3-based MLCCs with high capacitance

Multilayer ceramic capacitors (MLCCs) with high capacitance have great potentials in the battery charge-discharge circuit field. In this work, we fabricated a series of Ca-doped BaTiO
3
-based MLCCs with a high capacity of 47 μF and high reliability. With the incorporation of Ca
²⁺
, the temperature coefficient of capacity (TCC) is improved from X5R to X7R standard (EIA, Electronic Industries Alliance). We found that the samples formed the "core-shell" structure by TEM and EDS. Finally, we found that the samples with Ca
²⁺
doping concentration of 1.5 at.% have higher internal stress, which is responsible for the good temperature characteristics of the "core-shell" structure. Furthermore, the exceptional enhancement in the highly accelerated lifetime and reduction of oxygen vacancies confirm that the Ca
²⁺
dopant significantly enhances the reliability of dielectric ceramics in MLCCs. This study offers valuable insights and recommendations for further research on dielectric materials aimed at achieving high-performance and high-reliability MLCCs.