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Structure of the YBa 4 Cu 2 (CO 3 )O 5.5±δ Oxycarbonate
Author(s) -
Rodriguez M. A.,
Snyder R. L.,
Simmins J. J.,
Guo Y. M.,
Condrate Sr R. A.,
Rotella F. J.,
Jorgensen J. D.
Publication year - 1995
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s002188989401143x
Subject(s) - tetragonal crystal system , neutron diffraction , crystallography , powder diffraction , yttrium , materials science , rietveld refinement , perovskite (structure) , crystal structure , diffraction , chemistry , optics , physics , metallurgy , oxide
The crystal structure of the YBa 4 Cu 2 (CO 3 )O 5.5±δ (`142') oxycarbonate has been investigated by X‐ray and neutron powder diffraction techniques. X‐ray diffraction patterns indexed as a tetragonal P 4/ m unit cell with lattice parameters a = 8.1973 (4) and c = 8.0360 (5) Å. Rietveld refinements of powder neutron diffraction data indicated a distorted cubic perovskite cell in which yttrium and copper are arranged to yield a superlattice double that of the typical perovskite unit. Refinements indicate CO 2− 3 ions substituted on two of the four Cu sites in the proposed cell. Infrared spectroscopy results were consistent with neutron structural analysis, giving strong supporting evidence to the presence of two unique carbonate sites in the unit cell.