Abstract
In the present work, we studied the effects of substitutional Sm3+ ions on the ionic conduction properties of Li(5+2x)La(3)Nb(2-x)SmxO(12) (LLN-Sm) ceramics with x = 0.0-0.6. The investigated final ceramics, prepared by solid state reaction, were sintered at 1000 degrees C for 12 h. XRD investigations showed the formation of the cubic garnet phase for all of the studied samples. The ionic conductivity was found to increase with Sm3+ content, with the highest value of 7.04 x 10(-5) S/cm for the Li5+2xLa3Nb2-xSmxO12 sample compared to 7.49 x 10(-6) S/cm for the pure LLN sample, both at RT. Lithium ion mobilities of LLN-Sm garnets at different temperatures were estimated. Considerable enhancement of mobility, the main factor leading to ionic conductivity improvement, was obtained for samples with Sm3+ substitutions. Relaxation processes were studied by the electric modulus, and the corresponding activation energy was found to be very similar to the ionic conduction process.