Atomic-scale study on dysprosium doping in BaTiO3: Bridging observation and theory

Dysprosium doping of barium titanate is potentially relevant to the reliability of multilayer ceramic capacitors. To investigate this potential, we first predict the site-specific dysprosium doping behavior using density functional theory. Employing high-angle annular dark-field scanning transmission electron microscopy, we then report the first atomic-scale observations of dysprosium doping at both the barium and titanium sites in barium titanate, which have previously been only predicted. This direct observation overcomes the limitations of conventional indirect techniques and provides new insights into site-specific substitution of dysprosium atoms. Density functional theory calculations predict that dysprosium preferentially occupies the barium sites under thermodynamically stable conditions but favors titanium sites in specific local environments. The combined experimental and theoretical findings demonstrate that dysprosium doping induces lattice distortions and stabilizes oxygen vacancies, providing atomistic insight into defect behavior relevant to dielectric stability and reliability. These results establish a foundation for optimizing barium titanate-based dielectrics and advancing the design of multilayer ceramic capacitors.