Structural study of lithium titanogallate prepared by ion exchange via one-dimensional tunnel-like pathways

Neutron Rietveld refinement has been performed to elucidate structural chan ges due to Na+/Li+ exchange in one-dimensional tunnel-like cavities of sodi um titanogallate NaxTi2-xGa4+xO10(x approximate to 0.85). Cell parameters w ere anisotropically changed by ion-exchange; a, b and c have changed by - 0 .232, + 0.014 and - 0.039 Angstrom on substitution of Li+ for Na+ respectiv ely. Three L+ sites have been found in the Li-derivative; two of them are a little displaced from the two-fold rotation axis through the tunnel center , while the other is the deformed tetrahedral site fairly apart from the tu nnel center. These results are basically different from those for Na+ ions in the parent compound. (C) 1998 Elsevier Science B.V. All rights reserved.