CHARACTERIZATION OF STRUCTURE AND Li-IONIC CONDUCTIVITY OF La(2/3−x)Li3xTiO3 CERAMICS PREPARED BY SPARK PLASMA SINTERING

Abstract

In this work, La(2/3)-xLi3xTiO3 (LLTO) dense ceramic samples have been prepared by high-energy ball milling and spark plasma sintering (SPS) route. The crystal structures, microstructures of the samples were characterized by X-ray powder diffraction, FE-SEM, and their Li-ion conductive properties investigated by AC impedance spectroscopy. At 21 oC, the LLTO ceramic samples possessed the grain conductivity and grain boundary/total conductivity of σg = 8.3×10-4 S cm-1 and σgb = 2.3×10-5 S cm-1, respectively. In the research temperature range from 21 oC to 120 oC, the mechanism of ion conduction is thermally activated. The activation energies for grain and grain boundary conductivities are Eag = 0.26 eV and Eagb = 0.43 eV, respectively. Keywords: High energy mechanical milling, LLTO ceramics, Spark plasma sintering, Lithium ionic conductivity, Impedance Classification numbers: 81.05.Je, 81.20.Ev, 72.20.-i, 61.72.Mm, 82.47.Aa, 84.37.+q