Change in crystal structure and electron density by introducing oxygen in YBa{sub 2}Cu{sub 3}O{sub y} single crystal

Journal Article · Mon Mar 31 23:00:00 EST 1997 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7270· OSTI ID:543090

Jang, Wen-Jye; Mori, Hatsumi; Tajima, Setsuko ^[1]

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1. Superconductivity Research Lab., Tokyo (Japan); and others

The electron density map of tetragonal YBa{sub 2}Cu{sub 3}O{sub 6} (YBCO{sub 6}) single crystal was investigated, in comparison with that of orthorhombic YBa{sub 2}Cu{sub 3}O{sub 6.9} (YBCO{sub 6.9}). The crystal structure was determined by using four-circle X-ray diffraction data. The final values of the weighted reliability factor (R{sub W}) and unweighted factor (R) were 0.027 and 0.024 for YBCO{sub 6}, which are small enough for analysis of the Fourier difference maps. The obtained Fourier difference map shows a wide negative electron density region around Cu1 and no clear peak in the vicinity of Cu2-O3 plane, except for a negative peak between two Cu2 and O1. The introduction of O4 between two Cu1 atoms gives rise to substantial electron redistribution, creating negative and positive peaks around Cu1 and Cu2. There is no remarkable peak between Cu2 and O3 in YBCO{sub 6}, while a negative peak corresponding to the 3d{sub x2-y2} orbital electrons is found in YBCO{sub 6.9}. The former result for YBCO{sub 6} indicates that there is no clear bonding state within the CuO{sub 2} plane.

• OSTI ID: 543090
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 130; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
COPPER OXIDES
CRYSTAL STRUCTURE
ELECTRON DENSITY
HIGH-TC SUPERCONDUCTORS
MONOCRYSTALS
X-RAY DIFFRACTION
YTTRIUM OXIDES