Structures in the oxygen-deficient fluorite-related R{sub n}O{sub 2n-2} homologous series: Pr{sub 9}O{sub 16}
- Arizona State Univ., Tempe, AZ (United States)
- Los Alamos National Lab., NM (United States)
The crystal structure of the lower-temperature polymorph of the n = 9 member of the homologous series Pr{sub n}O{sub 2n-2}, Pr{sub 9}O{sub 16} ({zeta})m was determined utilizing Rietveld analysis of neutron time-of-flight powder diffraction data.The refined structure (P{bar 1}, a = 6.7396(8) {angstrom}, b = 8.711(1) {angstrom}, c = 6.6726(8) {angstrom}, a = 97.424(1) {angstrom}, {beta} = 99.973(1){degrees}, {gamma} = 75.301(1){degrees}, V = 371.7(1) {angstrom}{sup 3}; Z = 1; R{sub p} = 3.29%, and wR{sub p} = 4.64%) is an agreement with the model proposed on the basis of high-resolution electron microscopy. This structure is a superstructure of fluorite (F). The structural element is a pair of vacant oxygen sites separated by 1/2[111]{sub F} across a metal atom. These units are further apart from each other than those in the more reduced member of the series, Pr{sub 7}O{sub 12}. The existence of a higher-temperature form of Pr{sub 9}O{sub 16} was not confirmed.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 146456
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 118; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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