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

Abstract

Zinc doped calcium copper titanate, CaCu2.90Zn 0.10Ti4O12 (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 (εr ∼ 4317) than SWR2 and SR ceramics at room temperature. © 2013 Elsevier Ltd.