Crystallographic Studies and X-Ray Diffraction Patterns of Ba5R8Zn4O21 by Rietveld Refinements
Winnie K. Wong-Ng, James A. Kaduk, J Dillingham
The structure of the Ba5R8Zn4O21 series (R =lanthanides) was investigated using x-ray Rietveld refinements. The compounds were successfully prepared for R = Eu, Gd, Dy, Ho, Er, Tm, and Yb. For larger R, Ba5R8Zn4O21 was not stable, and tetragonal BaR2ZnO5 (La,Nd) and orthorhombic BaR2ZnO5 (Sm) phases were observed instead. Ba5R8Zn4O21 crystallizes in the tetragonal space group 14/m; for R=Yb to Eu, a ranges from 13.63502(5) to 13.96062(9) 3. The Zn2+ ions adopt a 5-fold distorted square pyramidal coordination. The 7-coordinate R3+ reside in monocapped trigonal prisms. These prisms share edges, and form layers stacked along the c-axis. There are two types of BaO polyhedra: bicapped square prisms (BaO10), and irregular BaO10 polyhedra.
, A., J.
and Dillingham, J.
Crystallographic Studies and X-Ray Diffraction Patterns of Ba<sub>5</sub>R<sub>8</sub>Zn<sub>4</sub>O<sub>21</sub> by Rietveld Refinements, Powder Diffraction
(Accessed June 1, 2023)