Crystallographic studies of perovskite-like compounds. IV. Rare earth scandates, vanadites, galliates, orthochromites

Abstract

Several seandates, vanadites, galliates and orthoehromites of several of the rare earth elements and yttrium are isostructural with Gd_FeO 3. The paper includes a summary discussion of the compounds so far studied in this series of papers. Particular emphasis is given the transitions which have b~en observed and the relations existing among the various compounds and among the three structural types to which they belong. Transition from the orthorhombic (Pbnm) to the rhombohedral (R-3m) structure has been found in SmA1Oa; thus the link to the ideal structure is through the rhombohedral. It is predicted that most of the orthorhombie compounds will not transform to the rhombohedral, and probably only one of the rhombohedral to the cubic structure.