eprintid: 1468469
rev_number: 32
eprint_status: archive
userid: 608
dir: disk0/01/46/84/69
datestamp: 2015-11-03 14:03:43
lastmod: 2021-11-08 00:10:14
status_changed: 2015-11-03 14:03:43
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Fortes, AD
title: Crystal structures of spinel-type Na2MoO4 and Na2WO4 revisited using neutron powder diffraction
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F57
keywords: neutron powder diffraction, sodium molybdate, sodium tungstate
note: This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
abstract: Time-of-flight neutron powder diffraction data have been collected from Na2MoO4 and Na2WO4 to a resolution of sin (θ)/λ = 1.25 Å(-1), which is substanti-ally better than the previous analyses using Mo Kα X-rays, providing roughly triple the number of measured reflections with respect to the previous studies [Okada et al. (1974 ▶). Acta Cryst. B30, 1872-1873; Bramnik & Ehrenberg (2004 ▶). Z. Anorg. Allg. Chem. 630, 1336-1341]. The unit-cell parameters are in excellent agreement with literature data [Swanson et al. (1962 ▶). NBS Monograph No. 25, sect. 1, pp. 46-47] and the structural parameters for the molybdate agree very well with those of Bramnik & Ehrenberg (2004 ▶). However, the tungstate structure refinement of Okada et al. (1974 ▶) stands apart as being conspicuously inaccurate, giving significantly longer W-O distances, 1.819 (8) Å, and shorter Na-O distances, 2.378 (8) Å, than are reported here or in other simple tungstates. As such, this work represents an order-of-magnitude improvement in precision for sodium molybdate and an equally substantial improvement in both accuracy and precision for sodium tungstate. Both compounds adopt the spinel structure type. The Na(+) ions have site symmetry .-3m and are in octa-hedral coordination while the transition metal atoms have site symmetry -43m and are in tetra-hedral coordination.
date: 2015-06-01
date_type: published
official_url: http://dx.doi.org/10.1107/S2056989015008774
vfaculties: VMPS
oa_status: green
full_text_type: pub
pmcid: PMC4459306
language: eng
primo: open
primo_central: open_green
article_type_text: Journal Article
verified: verified_manual
elements_source: Manually entered
elements_id: 1030306
doi: 10.1107/S2056989015008774
pii: wm5152
language_elements: eng
lyricists_name: Fortes, Andrew
lyricists_id: AFORT20
actors_name: Fortes, Andrew
actors_name: Barczynska, Patrycja
actors_id: AFORT20
actors_id: PBARC91
actors_role: owner
actors_role: impersonator
full_text_status: public
publication: Acta Crystallographica Section E
volume: 71
number: Pt 6
pagerange: 592-596
event_location: England
issn: 2056-9890
citation:        Fortes, AD;      (2015)    Crystal structures of spinel-type Na2MoO4 and Na2WO4 revisited using neutron powder diffraction.                   Acta Crystallographica Section E , 71  (Pt 6)   pp. 592-596.    10.1107/S2056989015008774 <https://doi.org/10.1107/S2056989015008774>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1468469/1/wm5152.pdf