Electrical and dielectric properties of optimized cubic structure with promising morphological texture in Ce_0.8Zr_0.2O₂

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 Ce_0.8Zr_0.2O₂ 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 Ce_0.8Zr_0.2O₂ were probed by applying ac electric field of different frequencies at variable temperatures. The measured dielectric constant of Ce_0.8Zr_0.2O₂ 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 ( \(\text{tan}\delta \) $\text{tan}\delta$ ). The interfacial polarization effect was confirmed by low-frequency dielectric dispersion in \({\varepsilon }^{{\prime}{\prime}}\) ${\epsilon }^{\prime \prime }$ and \( {\varepsilon }_{\rm r}\) ${\epsilon }_{\mathrm{r}}$ . The large conductivity coupled with a relaxation phenomenon at higher temperatures is attributed to the shift from extended hopping to localized ionic transport. Ce_0.8Zr_0.2O₂ 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.