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

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 mm 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 epsilon(r) approximate to 4347 along with the minimum value of tan delta approximate to 0.4 at 1 kHz.