Structure of Bi2Nd4O9 monoclinic phase

摘要

A new phase, Bi2Nd4O9, was synthesized in the binary system Bi2O3-Nd2O3 and structurally characterized from powder X-ray diffraction data. It crystallizes in monoclinic symmetry with lattice parameters a = 6.7037(2) Angstrom, b = 3.9062(1) Angstrom, 3.9542(1) Angstrom, beta = 125.258(1)degrees, Z = 2, and a subcell space group of C2/m. Its average structure had been determined by X-ray powder diffraction and refined by the Rietveld method, The average structure can be described as an oxygen-deficient fluorite structure of the delta-Bi2O3 type with Nd and Bi randomly distributed on the cation site, similar to Bi2La4O9 reported by Chen et al. (J. Solid State Chem. 124, 300 (1996)). In addition, a strong superstructure had been observed by transmission electron microscopy. (C) 2000 Academic Press. [References: 15]