Crystal Structure of Barium Titanate

Abstract

RECENTLY Rooksby¹ and Megaw² have reported a tetragonal structure for barium titanate. This is of interest to us because we also have obtained X-ray powder photographs of barium titanate, from which we have established a tetragonal structure. In addition we have obtained photographs of a lattice which at first was regarded as near cubic, though in view of our subsequent findings, it appears more correct to regard it as being near tetragonal. However, the reversible temperature change of structure from tetragonal to cubic reported by Miss Megaw² raises the question as to whether this cubic structure might not exist at ordinary temperatures, as a result of heat treatment, or method of preparation, or presence of impurities.