Dielectric and electrical properties of LiNbO3 ceramics

Li1-xNb1+x/5O3 (where x=0, 0.025, 0.045, 0.075) ferroelectric ceramics were prepared by the solid-state reaction method; X-ray diffraction patterns indicate that single phase was formed for pure LN ceramics. The electrical behavior of the ceramics was studied by impedance spectroscopy technique in the 300-1000 C temperature range. Impedance analysis was performed revealing a conductivity data which fitted in the modified power, sigma ac(omega) =A . omega(n)(1) +B . omega(n)2 and evidence of two types of conduction process. The low-frequency conductivity is due to long-range ordering (near frequency-independent) and high frequency conduction due to the localized orientation hopping mechanism. The static conductivity is determined for all compositions from Cole-Cole diagrams, and the evolution vs temperature is studied as a function of the Li/Nb ratio. (C) 2015 The Ceramic Society of Japan and the Korean Ceramic Society. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cleativecommons,orgi licensesiby-nc-nd/4,0/).