Thermal stability of dielectric properties of Dy-doped BaTiO3 for application in the ultra-thin multilayer ceramic capacitors

Rare earth elements are usually used to improve the performance of multilayer ceramic capacitors (MLCC), because their unique chemical and physical properties. Exploring the optimal method of rare earth doping is crucial to address the current performance deficiencies of MLCC. In this study, three samples with different doping levels of Dy and Ho selected to investigate the microstructure, dielectric performance, and reliability. Compared to the co-doping of Dy and Ho, excessive Dy doping exhibited better defect structure, resulting in smoother and more stable temperature coefficient of capacitance (TCC) curves and stronger suppression of oxygen vacancies. As the increase of Dy doping content, the activation energy of oxygen vacancies increased from 59.98 V/mu m to 86.79 V/mu m. This indicates that appropriate Dy doping has a superior effect on improving MLCC performance compared to co-doping systems. This work validates the complex defect structure induced by Dy doping and its improvement effect on MLCC performance, demonstrating the significant potential of Dy-doped MLCC.