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 Fe3þ, Cr3þ and Ni2þ for Ti4þ 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. # 2003 Elsevier B.V. All rights reserved