Electrical and dielectric properties of optimized cubic structure with promising morphological texture in Ce0.8Zr0.2O2.

Influence of structure and microstructure on the dielectric properties of single-phase solid solution of ZrO2–CeO2 system with 80% CeO2 has been investigated. Highly dense polycrystalline Ce0.8Zr0.2O2 ceramic was synthesized through solid-state reaction route, and its cubic structure was verified through X-ray diffraction and Raman spectroscopy techniques. The compact grain morphology was validated through FESEM with grain size of ~9 μm. Dielectric properties of the Ce0.8Zr0.2O2 were probed by applying ac electric field of different frequencies at variable temperatures. The measured dielectric constant of Ce0.8Zr0.2O2 in the presence of applied ac field of 2 kHz frequency at 300 K is ~1819, is reduced to 27 with an increase in the frequency up to 2 MHz, which is a comparatively high dielectric constant than binary oxides. The high packing fraction of cubic structure of ZrO2–CeO2 with 80% CeO2 showed a small dielectric loss ( tan δ ). The interfacial polarization effect was confirmed by low-frequency dielectric dispersion in ε ′ ′ and ε r . The large conductivity coupled with a relaxation phenomenon at higher temperatures is attributed to the shift from extended hopping to localized ionic transport. Ce0.8Zr0.2O2 showed a negative coefficient of resistance validated through increasing ac conductivity with temperature. A high dielectric constant with small dielectric tangent loss achieved in cubic structured sample established its application in high-performance metal oxide semiconductor field effect transistor (MOSFET) devices along with the formation of advanced solid-electrolytes for solid oxide fuel cells. [ABSTRACT FROM AUTHOR]