Influence of Zn doping on microstructures and dielectric properties in CaCu 3Ti 4O 12 ceramic synthesised by semiwet route

Abstract

A single phase of calcium copper titanate [CaCu 3Ti 4O 12 (CCTO)] was produced at lower temperature and shorter calcination time via a novel semiwet route. Undoped CCTO and zinc doped CaCu 3-xZn xTi 4O 12 samples with x=0·10, 0·20 and 0·30 were prepared by this method for the first time using solid TiO 2 powder in metal nitrate solutions. The CaCu 3-xZn xTi 4O 12 ceramics were characterised by thermogravimetric/differential thermal analysis, X-ray diffraction, SEM and EDX techniques. The SEM images of the sintered CaCu 3-xZn xTi 4O 12 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. CaCu 3-xZn xTi 4O 12 (x=0·20) ceramic has the maximum value of ε r≈4347 along with the minimum value of tan δ≈0·14 at 1 kHz. © 2012 Institute of Materials, Minerals and Mining.