The Crystal Structure of BaY2O4, Isotypic with SrY2O4

Abstract Since the discovery of the superconductivity in Ba 2 YCu 3 O 7-x , the system Ba-Y-Cu-O has generated vast interest. The presence and the properties of the intermediate phases were examined, and the existence of the BaY 2 O 4 phase was confirmed. We have determined the crystal structure of this material from powder data; it is orthorhombic, Pnma (no 62) with a = 10.394(3) Å, b = 3.450(1) Å, c = 12.113(4) Å, isotypic with SrY 2 O 4 (CaFe 2 O 4 -type). The observed and calculated intensity values are reported together with the powder diffraction data, obtained both by Guinier and diffractometer methods.