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X-Ray Absorption Spectroscopy and Computer Modelling Study of Nanocrystalline Binary Alkaline Earth Fluorides

Chadwick, Alan V., Düvel, A., Heitjans, P., Pickup, D.M., Ramos, Silvia, Sayle, D.C., Sayle, T.X.T. (2015) X-Ray Absorption Spectroscopy and Computer Modelling Study of Nanocrystalline Binary Alkaline Earth Fluorides. IOP Conference Series: Materials Science and Engineering, 80 . 012005. ISSN 1757-899X. (doi:10.1088/1757-899X/80/1/012005) (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)

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. (Contact us about this Publication)
Official URL
http://doi.org/10.1088/1757-899X/80/1/012005

Abstract

Nanocrystalline samples of Ba1-xCaxF2 prepared by high-energy milling show an unusually high F? ion conductivity, which exhibit a maximum in the magnitude and a minimum in the activation energy at x = 0.5. Here, we report an X-ray absorption spectroscopy (XAS) at the Ca and Sr K edges and the Ba L3 edge and a molecular dynamics (MD) simulation study of the pure and mixed fluorides. The XAS measurements on the pure binary fluorides, CaF2, SrF2 and BaF2 show that high-energy ball-milling produces very little amorphous material, in contrast to the results for ball milled oxides. XAS measurements of Ba1-xCaxF2 reveal that for 0 < x <1 there is considerable disorder in the local environments of the cations which is highest for x = 0.5. Hence the maximum in the conductivity corresponds to the composition with the maximum level of local disorder. The MD calculations also show a highly disordered structure consistent with the XAS results and similarly showing maximum disorder at x = 0.5.

Item Type: Article
DOI/Identification number: 10.1088/1757-899X/80/1/012005
Uncontrolled keywords: Physics of Quantum Materials
Subjects: 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 10:31 UTC
Last Modified: 17 Jul 2019 09:59 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/48084 (The current URI for this page, for reference purposes)
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