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<p>The effect of the grain size on the dielectric properties and electrical conductivity was studied for single-phase solid solution of the ZrO<sub>2</sub>–CeO<sub>2</sub> system with 75% CeO<sub>2</sub>. The bi-ceramic composition of ZrO<sub>2</sub>–CeO<sub>2</sub> as Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub> was prepared through a solid-state reaction to synthesize single-phasic material followed by high-energy ball milling to make finer particle size. Structural properties were confirmed through advanced analytical techniques such as XRD and Raman spectroscopy. SEM confirmed large porosity with a grain size of 204 ± 3 nm, which is larger than the crystallite size of 22.64 ± 8.6 nm calculated from the XRD analysis for Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub>. The dielectric measurements were performed as a function of temperature by impedance spectroscopy. The relative dielectric constant decreases on increasing frequency for all temperatures, which validates the polar nature of nanocrystalline Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub> ceramic. In addition, temperature-dependent enhancement in <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12034_2024_3387_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\({\varepsilon }_{\text{r}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ε</mi> <mtext>r</mtext> </msub> </math></EquationSource> </InlineEquation> is more pronounced in low-frequency regions due to low-frequency dielectric dispersion phenomena. The dielectric loss also increases with increasing temperature over the frequency region from 100 Hz to 2 MHz. The electrical conductivity of nanocrystalline Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub> was found to be smaller than the micron-sized sample of Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub>. The present study revealed the crucial role of grain size in tuning the dielectric properties of Ce<sub>0.75</sub>Zr<sub>0.25</sub>O<sub>2</sub> along with ac conductivity.</p>

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Impedance spectroscopic study on nanocrystalline Ce0.75Zr0.25O2 ceramics

  • 期刊论文

  • 发表日期：

    2025年1月11日

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  • Sushama Kumari,
  • S K Sharma,
  • Ramcharan Meena,
  • Vijay Kumar Goel,
  • Swati Bugalia

摘要

The effect of the grain size on the dielectric properties and electrical conductivity was studied for single-phase solid solution of the ZrO2–CeO2 system with 75% CeO2. The bi-ceramic composition of ZrO2–CeO2 as Ce0.75Zr0.25O2 was prepared through a solid-state reaction to synthesize single-phasic material followed by high-energy ball milling to make finer particle size. Structural properties were confirmed through advanced analytical techniques such as XRD and Raman spectroscopy. SEM confirmed large porosity with a grain size of 204 ± 3 nm, which is larger than the crystallite size of 22.64 ± 8.6 nm calculated from the XRD analysis for Ce0.75Zr0.25O2. The dielectric measurements were performed as a function of temperature by impedance spectroscopy. The relative dielectric constant decreases on increasing frequency for all temperatures, which validates the polar nature of nanocrystalline Ce0.75Zr0.25O2 ceramic. In addition, temperature-dependent enhancement in \({\varepsilon }_{\text{r}}\) ε r is more pronounced in low-frequency regions due to low-frequency dielectric dispersion phenomena. The dielectric loss also increases with increasing temperature over the frequency region from 100 Hz to 2 MHz. The electrical conductivity of nanocrystalline Ce0.75Zr0.25O2 was found to be smaller than the micron-sized sample of Ce0.75Zr0.25O2. The present study revealed the crucial role of grain size in tuning the dielectric properties of Ce0.75Zr0.25O2 along with ac conductivity.