Fabrication and characterization of CdCu3Ti4O12 ceramics with colossal permittivity and low dielectric loss

Abstract

CdCu3Ti4O12 (CdCTO) ceramics were fabricated using a sol–gel technique, which performed an unconventional giant permittivity (GP) and low dielectric loss: εr≈6.0×104 and tan δ=0.056 (at 1kHz). The abnormal dielectric peaks could be ascribed to the contribution of doubly-ionized oxygen vacancies at high temperature range. In addition, the GP phenomenon of CdCTO ceramics were attributed to the internal barrier layer capacitor (IBLC) theory. The results of X-ray photoelectron spectroscopy (XPS) indicated the mixed valence states of Cu+/Cu2+ and Ti3+/Ti4+ of samples.