Dielectric response of Sb-doped CaCu3Ti4O12 ceramics

A series of Sb-doped CaCu3Ti4O12 ceramics were fabricated by the conventional solid state method, and their crystalline structures, microstructures and dielectric properties were investigated systematically. All the ceramic samples exhibited perovskite-related structures in space group Im . The grain size decreased slightly as Sb concentration increased; whereas the dielectric permittivity of the ceramics increased slightly. The giant dielectric response was considered to be closely related with a reduction in the potential barrier height at grain boundaries (GBs). The activation energy for the dc conduction process is comparable to that for conduction at GBs, indicating that the dc conduction process is associated with the electrical response of GBs.