Exceptional dielectric performance of MLCCs enabled by defect-engineered BaTiO3

Abstract

Gaining an in-depth understanding of the effect of the Ba/Ti ratio on the performance of BaTiO₃ (BT)-based multilayer ceramic capacitors (MLCCs) from the viewpoint of defect chemistry is challenging owing to the doping diversity and complexity. This study focused on the dielectric properties based on the Ba/Ti ratio, which are mainly determined by reversible and irreversible domains. The sample with Ba/Ti < 1 had a larger shell proportion and lower reversible domain concentration than that with Ba/Ti > 1, which is attributed to Ba vacancies having a higher diffusion rate than Ti vacancies . Furthermore, different pinning abilities resulted in different irreversible domain concentrations. When Dy was doped in Ti sites for materials with Ba/Ti > 1, it formed defects , , and , exhibiting a stronger pinning ability than and formed in the case of Ba/Ti < 1 and Dy doped in the Ba site.