Solid State Ionics, Vol.256, 29-37, 2014
Sintering effect on electrical properties of Li2TiO3
We present in this article, the latest development in electrical properties of lithium titanate (Li2TiO3) with different sintering (800 degrees C, 900 degrees C and 1000 degrees C), which were prepared by high-energy ball milling technique. The transformation of beta(monoclinic) -> gamma(cubic) phase, average crystallite size and lattice strain of Li2TiO3 ceramic at various temperatures are evaluated by X-ray diffraction patterns. The electrical properties are characterized by Ac impedance spectroscopy and the experimental results show low activation energy (E-a) and high AC conductivity in the range of 10(-3) Scm(-1) for all samples at 1 MHz frequency. The E-a value, with respect to Ac conductivity at 10 kHz frequency, is approximately equal to the E-a value of relaxation time (tau). The surface microstructure analysis of all sintered samples were characterized by SEM, and good crystalline nature was observed at the 1000 degrees C sintered sample. The temperature dependence of AC conductivity distinctly indicates the negative temperature coefficient of resistance (NTCR) behavior. Conductivity mechanisms were interpreted by the frequency exponents (n(1), n(2)) evaluated with the double power law followed by the Arrhenius relation. (C) 2014 Elsevier B.V. All rights reserved.