Crystal Structure of Nd2BaCu3O7.3 Determined from X-ray and Neutron Powder Diffraction Data

  • 10.1021/cm990021w
  • Chem. Mater.
  • p 3-4, 11 (12),
In the present paper we report crystal structure of insulating compound Nd 1.9 Ba 1.1 Cu 3 O 7.28 the Nd-rich terminating point of Nd 1+ x Ba 2 - x Cu 3 O z solid solutions. This phase has an orthorhombic lattice with a = 3.8565(1) Å, b = 7.7724(3) Å, c = 22.9862(8) Å. The space group Ammm was determined on the basis of IR and Raman spectroscopic data and electron diffraction analysis. The crystal structure was solved and refined from the powder XRD and time-of-flight neutron diffraction data. Neodymium atoms on the barium site compared to conventional NdBa 2 Cu 3 O 7 crystal are ordered and form a face-centered supercell, while additional oxygen atoms occupy vacant chain sites in the vicinity of barium atoms.