Microstructure, dielectric and pyroelectric properties of CaCu3Ti4O12 ceramics fabricated by tape-casting method

• CaCu3Ti4O12 ceramics were prepared by tape-casting method.
• The sintering temperature effects on the microstructures and dielectric properties.
• The activation energy of dielectric relaxation was close to dc conductivity.
• The polarons induced by oxygen vacancies are responsible for electrical responses.
• The measured pyroelectric effect shows ferroelectriclike nature of CCTO ceramics.

CaCu3Ti4O12 (CCTO) ceramics were prepared by tape-casting method. All the ceramics exhibited body-centered cubic structure. A homogeneous microstructure with clear grain boundaries was obtained by tuning the sintering temperature. The dielectric properties of CCTO were investigated in a temperature range of −100 to +300 °C. A relaxation has been observed in the frequency range higher than 100 kHz, the activation energy was found to be 0.07 eV, close to that of the activation energy for dc conductivity (0.08 eV) at low temperatures. It suggests that the polarons induced by oxygen vacancies are responsible for the conduction and relaxation process. The high-temperature dependence of the dc conductivity associated with oxygen vacancies. Also, the hysteresis loop and pyroelectric properties have been measured and the incidence of the pyroelectric effect associated with the temperature dependence of pyroelectric coefficient implies that CCTO has a vast potential in the field of high-temperature pyroelectric thermal detectors.

Figure optionsDownload as PowerPoint slide