Dielectric properties of CaCu 2·9 Co 0·1 Ti 4 O 12 and CaCu 3 Ti 3·9 Co 0·1 O 12 ceramics synthesized by semi-wet route

The effect of Co +2 doping on Cu +2 and Ti +4 sites in calcium copper titanate, CaCu3Ti4O12 ,h as been examined. The doped compositions, CaCu3−xCoxTi4O12 and CaCu3Ti4−xCoxO12 (x = 0·10) ceramics, were pre- pared by novel semi-wet route. In this method, calcium, copper and cobalt salts were taken in solution form and TiO2 was used in solid form. XRD analysis confirmed the formation of single-phase materials. Structure of CaCu3Ti4O12 does not change on doping with cobalt either on Cu-site or Ti-site and it remains cubic. Scanning electron micro- graphs (SEM) show average grain size of CaCu2·9Co0·1Ti4O12 to be larger than CaCu3Ti3·9Co0·1O12 ceramic. Energy dispersive X-ray spectroscopy (EDX) studies confined the purity of parent and Co-doped CaCu3Ti4O12 ceramics. Dielectric constant (er) and dielectric loss (tan δ )o f CaCu2·9Co0·1Ti4O12 is comparatively higher than that of CaCu3Ti3·9Co0·1O12 ceramic at all measured frequencies and temperatures.