Dielectric properties of CaCu3Ti4−xCoxO12 (x = 0.10, 0.20, and 0.30) synthesized by semi-wet route

Undoped CaCu₃Ti₄O₁₂ and cobalt doped CaCu₃Ti_4−xCo_xO₁₂ (CCTCO) with x = 0.10, 0.20 and 0.30 were prepared by semi-wet route for the first time using solid TiO₂ powder and metal nitrate solutions. XRD analysis confirmed the formation of single-phase material in the samples sintered at 900 °C for 6 h. Structure does not change on doping with cobalt and it remains cubic in all the three compositions studied. Lattice parameter increases slightly with cobalt doping. SEM micrographs of the CaCu₃Ti_4−xCo_xO₁₂ samples show that the grain size is in the range of 2–8 μm for these samples. EDX studies show the percentage of elements along with the grain and grain boundary, which confirm the rich phase of copper oxide at grain boundaries. Dielectric properties have been measured as a function of temperature and frequency.