Influence of the Cation Distribution on the Physical Properties of the Diluted Magnetics Li1.33Ti1.67O4/Co2TiO4
Spinel samples of Li1.33xCo2-2xTi1+0.67xO4 crystallize in two space groups: Fd- 3 m for 0≤x≤0.40 and x=1, and P4332 for 0.50≤x≤0.875. In S.G. P4332 magnetic Co2+ ions occupy 8c sites (for x=0.75 and 0.875), or 8c, 4b and 12d sites (for x=0.50). In x=0.25 and 0.40 samples Co2+ occupy both 8a and 16d cation sites of the S.G. Fd- 3 m . Observed differences in magnetic behaviour of the samples are induced by crystallographic distribution of Co2+. Possible paths for exchange interactions in S.G. P4332 were analysed. It was found that the superexchange is the dominant exchange mechanism where Co2+ (8c)-O(24e)-Co2+(12d) path was the most important one. On the basis of the results on crystallographic distribution we suggest x=0.50 sample as potential electrode material in Li ion rechargeable batteries.
Yvonne Andersson, Eric J. Mittemeijer and Udo Welzel
B. Antić et al., "Influence of the Cation Distribution on the Physical Properties of the Diluted Magnetics Li1.33Ti1.67O4/Co2TiO4", Materials Science Forum, Vols. 443-444, pp. 371-374, 2004