Dielectric properties of CaCu_(2.9)Co_(0.1)Ti_4O_(12) and CaCu_3Ti_(3.9)Co_(0.1)O_(12) ceramics synthesized by semi-wet route

摘要

The effect of Co~(+2) doping on Cu~(+2) and Ti~(+4) sites in calcium copper titanate, CaCu_3Ti_4O_(12), has been examined. The doped compositions, CaCu_(3-x)Co_xTi_4O_(12) and CaCu_3Ti_(4-x)Co_xO_(12) (x = 010) ceramics, were prepared by novel semi-wet route. In this method, calcium, copper and cobalt salts were taken in solution form and TiO_2 was used in solid form. XRD analysis confirmed the formation of single-phase materials. Structure of CaCu_3Ti_4O_(12) does not change on doping with cobalt either on Cu-site or Tl-site and it remains cubic. Scanning electron micrographs (SEM) show average grain size of CaCu_(2.9)Co_(0.1)Ti_4O_(12) to be larger than CaCu_3Ti_(3.9)Co_(0.1)O_(12) ceramic. Energy dispersive X-ray spectroscopy (EDX) studies confined the purity of parent and Co-doped CaCu_3Ti_4O_(12) ceramics. Dielectric constant (ε_r) and dielectric loss (tan δ) of CaCu_(2.9)Co_(0.1)Ti_4O_(12) is comparatively higher than that of CaCu_3Ti_(3.9)Co_(0.1)O_(12) ceramic at all measured frequencies and temperatures.