Local Structure of Sodium- and Iron-deintercalated NaFeAs

Cassidy, Simon J. and Ramos, Silvia and Clarke, Simon J. (2014) Local Structure of Sodium- and Iron-deintercalated NaFeAs. Zeitschrift für anorganische und allgemeine Chemie, 640 (14). pp. 2889-2896. ISSN 0044-2313. (doi:https://doi.org/10.1002/zaac.201400343) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://doi.org/10.1002/zaac.201400343

Abstract

The local structures around Fe and As were probed using X-ray absorption spectroscopy in metastable derivatives of NaFeAs obtained by deintercalation of the metals with iodine in THF at room temperature. The deintercalated product with a defective ThCr2Si2 structure is unattainable through conventional high temperature routes due to the size-mismatch between the eight-coordinate site and the Na+ radius in the ThCr2Si2 structure type, and is poorly crystalline. X-ray absorption Near Edge Structure (XANES) measurements show a shift of the Fe K-edge consistent with oxidation of iron to the +3 oxidation state. Changes to the features in the XANES at the As K-edge and analysis of the Extended X-ray Absorption Fine Structure (EXAFS) data from both Fe and As K-edges show that the local structures of Fe and As may only be modelled adequately using a highly defective ThCr2Si2 structural model. This shows that deintercalation of both Na and Fe from NaFeAs occurs to produce NaFe1.7As2, which shares local structural features with the related iron selenides K0.8Fe1.6Se2.

Item Type: Article
Additional information: Special Issue: Dedicated to Professor Martin Jansen on the Occasion of His 70th Birthday
Uncontrolled keywords: Superconductors;Iron;Deintercalation;Local Structure;XANES;EXAFS
Subjects: Q Science > QC Physics > QC176 Solid state physics
Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Silvia Ramos
Date Deposited: 28 Apr 2015 10:00 UTC
Last Modified: 10 Dec 2017 12:43 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/48080 (The current URI for this page, for reference purposes)
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