X-Ray and Neutron Powder Diffraction Studies of (Ba1-xSrx)Y2CuO5
Zhi Yang, Winnie K. Wong-Ng, James A. Kaduk, Qingzhen Huang, Lawrence P. Cook
This paper reports the results of the crystallography and crystal chemistry investigation of the (Ba1-xSrx)Y2 CuO5 ( green phase ) solid solution series by x-ray powder diffraction (XPD) and neutron powder diffraction (NPD) methods. The single phase region of (Ba1-xSrx)Y2 CuO5 was determined to be 0 ?x ? 0.3 (prepared at 810?C in 100 Pa pO2) and 0 ?x ? 0.7 (prepared at 930?C in air). All single phase (Ba1-xSrx)Y2 CuO5 samples are isostructural to BaY2CuO5 and can be indexed using an orthorhombic cell with the space group Pnma. Lattice parameters, a, b, c and the cell volume, V, of the (Ba1-xSrx)Y2 CuO5 members decrease linearly with increasing Sr substitution (x) on the Ba site. The general structure of (Ba1-xSrx)Y2 CuO5 can be considered as having a 3-dimensional interconnected network of [YO7], [(Ba,Sr)O11], and [CuO5] polyhedra. The copper ions are located inside distorted [CuO5] square pyramids. These pyramids are connected by the [Y2O11] groups that are formed from two monocapped [YO7] trigonal prisms sharing a triangular face. The Ba2+ atoms are found to reside in distorted 11-fold coordinated cages. The oxygen sites are essentially fully occupied. X-ray reference powder reference patterns of two members of the series, (Ba.3Sr.7)Y2 CuO5 and (Ba.7Sr.3)Y2 CuO5, were prepared for inclusion in the Powder Diffraction File (PDF).
(Ba<sub>1-x</sub>Sr<sub>x</sub>)Y<sub>2</sub>CuO<sub>5</sub>, crystal structure and crystal chemistry, Rietveld refinements, x-ray and neutron powder diffraction, x-ray reference
, Wong-Ng, W.
, A., J.
, Huang, Q.
and Cook, L.
X-Ray and Neutron Powder Diffraction Studies of (Ba<sub>1-x</sub>Sr<sub>x</sub>)Y<sub>2</sub>CuO<sub>5</sub>, Powder Diffraction
(Accessed September 22, 2023)