Effect of nickel substitution on electrical and microstructural properties of CaCu3Ti4O12 ceramic

In this paper we study CaCu3Ti4O12 doped with Ni on copper site. We focus particularly on the effect of the substitution amount and the sintering parameters on the grain growth, morphological evolution, dielectric constant and resistivity. Compositions with formula CaCu3-xNix Ti4O12 with x = 0, 0.05, 0.075, 0.1, 0.2 and 0.3 were prepared by conventional solid state reaction method. The samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dielectric measurements were taken at room temperature in the 10(2) Hz - 10(7) Hz frequency range. XRD analysis confirmed the formation of a single phase material in the samples calcined at 1000 degrees C for 12 h with x <= 0.2 and indicated the presence of secondary phases such as CuO, CaTiO3 and TiO2 in other with x > 0.2. In all compositions, structure remained cubic. The dielectric properties such as permittivity, loss factor and resistivity of these ceramics were improved and interpreted. (C) 2016 Elsevier B.V. All rights reserved.