Electronic parameters of Sr{sub 2}Nb{sub 2}O{sub 7} and chemical bonding
- National Laboratory for Sustainable Energy, Materials Research Department, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)
- Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk 90 (Russian Federation)
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234 (Australia)
X-ray photoelectron spectroscopy (XPS) measurements were carried out on a strontium pyroniobate (Sr{sub 2}Nb{sub 2}O{sub 7}) powder sample, which was synthesized using standard solid-state method. The binding energy (BE) differences between the O 1s and cation core levels, {delta}(O-Nb)=BE(O 1s)-BE(Nb 3d{sub 5/2}) and {delta}(O-Sr)=BE(O 1s)-BE(Sr 3d{sub 5/2}), were used to characterize the valence electron transfer on the formation of the Nb-O and Sr-O bonds. The chemical bonding effects were considered on the basis of our XPS results for Sr{sub 2}Nb{sub 2}O{sub 7} and earlier published structural and XPS data for other Sr- or Nb-containing oxide compounds. The new data point for Sr{sub 2}Nb{sub 2}O{sub 7} is consistent with the previously derived relationship for a set of Nb{sup 5+}-niobates that {delta}(O-Nb) increases with increasing mean Nb-O bond distance, L(Nb-O). A new empirical relationship between {delta}(O-Sr) and L(Sr-O) was also obtained. Interestingly, the correlation between {delta}(O-Sr) and L(Sr-O) was found to differ from that between {delta}(O-Nb) and L(Nb-O). Possible cause for the difference is discussed. - Graphical abstract: Layered crystal structure of Sr{sub 2}Nb{sub 2}O{sub 7}.
- OSTI ID:
- 21128309
- Journal Information:
- Journal of Solid State Chemistry, Vol. 181, Issue 6; Other Information: DOI: 10.1016/j.jssc.2008.01.046; PII: S0022-4596(08)00064-9; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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