Characterization of nickel doped CCTO: CaCu2.9Ni0.1Ti4O12 and CaCu3Ti3.9Ni0.1O12 synthesized by semi-wet route

Nickel doped CaCu3Ti4O12 (CCTO) samples, i.e. CaCu2.9Ni0.1Ti4O12 (CCNTO) and CaCu3Ti3.9Ni0.1O12 (CCTNO) were prepared by semi-wet route using TiO2 powder and metal nitrate solutions. According to both the stoichiometry, structure does not change on doping with nickel in both the samples and it remains cubic. Scanning electron micrographs (SEM) show that the grain size for both doped samples is in the range of 10-50 mu m. Energy dispersive X-ray spectrometer (EDX) studies confirmed the presence of copper rich phase at grain boundaries. X-ray photoelectron spectroscopy (XPS) studies confirm the presence of Cu2+ and Ti4+ in both the samples of nickel doped CCTO ceramics. Dielectric constant (epsilon(r)) and dielectric loss (tan delta) of Ni doped sample in CCTO on copper site is comparatively more than the Ni doped on titanium site sample. (C) 2009 Elsevier B.V. All rights reserved.