Combinatorial approach for powder preparation of pseudo-ternary system LiO0.5-X-TiO2 (X:FeO1.5, CrO1.5 and NiO)

Pseudo-ternary compounds of LiO0.5-X-TiO2 (X: FeO1.5, CrO1.5 and NiO) system were prepared using a fully automatic combinatorial robot system with the following functions: weighing and mixing of starting materials, heat treatment, and X-ray diffraction analysis. The following crystal structures were obtained by means of heat treatment at 1373 K: ramsdellite, spinel, pseudobrookite, rock salt, hematite and rutile. Furthermore, the composition range of the products with a ramsdellite-type structure in LiO0.5-X-TiO2 (X: FeO1.5, CrO1.5 and NiO) system was considered to have a relationship to the ionic radii of the substitutional transition metals Fe-,(3+) Cr3+ and Ni2+ for Ti4+ in octahedral site. It was found that solubility limits of 3d elements in lithium titanium oxide with ramsdellite structure were investigated in a shorter time by combinatorial method. (C) 2003 Elsevier B.V. All rights reserved.