Analysis of structural and electrical properties of Ni2+:Zn2SiO4 ceramic powders by sol-gel method

Present paper reports on the synthesis and electrical properties of Ni2+:Zn2SiO4 (Zn2-xSiO4 = xNi(2+), x = 0.0, 0.25, 0.50 and 0.75 mol%) ceramic powders by a conventional sol-gel method. The structural details of Ni2+:Zn2SiO4 ceramic powders have been investigated from the measurement of XRD, FT-IR, Raman spectral profiles and SEM images. The results reveal that these ceramic powders are all in nanometer sized-grains of spherical forms with willemite structures. The XRD and EDAX results have thus corroborated the successful doping of Ni2+ ions into the Zn2SiO4 matrix. The dielectric real (epsilon'), imaginary (epsilon aEuro(3)) parts, loss tangent (tan delta) and AC conductivity (sigma(ac)) properties as the function of frequency have been carried out and those are strongly dependent on Ni concentration and this behaviours have been explained on the basis of Maxwell-Wagner type of interfacial space charge polarization. Complex impedance analysis data shows only one semicircle corresponding to the grain boundary volume and thus suggesting that the conduction occurrence through grain boundary volume in Ni2+ doped samples and it has been explained using the Cole-Cole expression. .