Influence of Zn doping on microstructures and dielectric properties in CaCu3Ti4O12 ceramic synthesised by semiwet route

Abstract

A single phase of calcium copper titanate [CaCu3Ti4O12 (CCTO)] was produced at lower temperature and shorter calcination time via a novel semiwet route. Undoped CCTO and zinc doped CaCu3−xZnxTi4O12 samples with x = 0·10, 0·20 and 0·30 were prepared by this method for the first time using solid TiO2 powder in metal nitrate solutions. The CaCu3−xZnxTi4O12 ceramics were characterised by thermogravimetric/differential thermal analysis, X-ray diffraction, SEM and EDX techniques. The SEM images of the sintered CaCu3−xZnxTi4O12 ceramics showed average grain size in the ranges of 2–6, 8–13, 12–16 and 14–20 μm for x = 0·00, 0·10, 0·20 and 0·30 respectively. Energy dispersive X-ray spectroscopy studies confirm the purity of parent and Zn doped CCTO ceramics. At room temperature, the dielectric constants of Zn doped CCTO are always higher than pure CCTO. CaCu3−xZnxTi4O12 (x = 0·20) ceramic has the maximum value of ϵr≈4347 along with the minimum value of tan δ≈0·14 at 1 kHz.