By doping a few atomic percent of 3d -block cations, we demonstrate that the high dielectric response in Ca Cu3 Ti4 O12 can be reduced by a factor of ∼ 103 at room temperature. Each of the added dopants shows its own preferential substitution on either Cu or Ti sites. The dopants that act as acceptors have a critical impact on the disappearance of the electrostatic potential barrier at grain boundaries, resulting in drastically decreased permittivity values of <90 without voltage dependence. The present doping experiment directly shows that the potential barrier at internal interfaces is a key factor for the peculiar dielectric phenomena.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)