Dielectric properties of zinc doped nanocrystalline calcium copper titanate synthesized by different approach

Zinc doped calcium copper titanate, CaCu2.90Zn0.10Ti4O12 (CCZTO), nanocrystalline electro-ceramics synthesized by solution-wet route (SR) as well as semi-wet route using citric acid (SWR1) and glycine (SWR2) separately, were characterized by TGA/DTA, XRD, TEM, SEM and EDX techniques. The crystallite sizes of the ceramics obtained by XRD were found to be in the range of 45–90 nm is in good agreement with those observed by TEM analysis. The grain sizes for the ceramics SWR1, SWR2 and SR observed by SEM were found in the range of 10–15 μm, 1–4 μm, and 2–4 μm, respectively. Thermal studies show that the single phase CCZTO ceramic was formed in single step combustion reaction in SWR2 while in the case of SWR1 and SR were obtained in multistep reactions. SWR2 route shows more effective solid state reaction for the formation of nanocrystalline CCZTO single phase at much lower sintering temperature. SWR1 ceramic exhibits higher dielectric constant (ɛr ∼ 4317) than SWR2 and SR ceramics at room temperature.

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► CCZTO ceramic was synthesized by solution route as well as semi-wet routes.
► TG shows that single phase of SWR2 ceramic is formed around 450 °C in a single step.
► Crystallite size obtained by XRD and TEM were found to be in the range of 45–90 nm.
► Glycine combustion is better than citric acid combustion for synthesis of ceramic.
► Dielectric properties of CCZTO are extremely sensitive to preparation methodology.