Sandwich-structured BaTiO3/Ag ceramics embedded with a negative-epsilon layer to obtain high permittivity and suppress dielectric loss

Ceramic-based dielectrics with high permittivity have extensive applications in energy storage, electronic devices, communication, and other fields. However, ceramics with high permittivity based on the classical percolation theory design often have a substantial dielectric loss. To address this contradiction, we designed a sandwich structure with a negative dielectric layer. The sandwich structure comprises BaTiO3/Ag ceramics with different silver contents. The intermediate layer of the sandwich structure is composed of materials with negative permittivity, and adding a negative-epsilon layer enhances the interfacial polarization, increasing permittivity. More importantly, the multi-layer structure hinders the formation of conductive paths along the electric field direction between layers, positively suppressing dielectric loss. When the permittivity reaches 8000, the dielectric loss still does not exceed 0.02. This work provides a new approach to designing dielectric ceramics with high permittivity and low dielectric loss.