CRYSTAL-STRUCTURE OF LIKCO3 BY NEUTRON POWDER DIFFRACTION ANALYSIS

The crystal structure of LiKCO3 was determined by neutron powder diffr action. A final weighted R-factor of 4.54% was obtained for the refine ment of 2373 reflections by the Rietveld method from a sample synthesi zed using (Li2CO3)-Li-7 and K2CO3 (99.9% pure). Slight distortion of t he CO32- units in the monoclinic cell was observed; the O(1)-C-O(2) an gle and C-O(3) length are larger than the other C-O bond lengths and O -C-O angles. These local-structure characteristics can be explained by the difference in the ionic size of Li+ and K+, and the different ele ctrostatic interactions between the cations and CO32- units. (C) 1997 Academic Press.