Pristine and hydrated fluoroapatite (0001)
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Published:2019-09-10
Issue:5
Volume:75
Page:830-838
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ISSN:2052-5206
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Container-title:Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials
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language:
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Short-container-title:Acta Crystallogr Sect B
Author:
Torrelles XavierORCID,
Nadeem Immad M.,
Kupka Anna,
Crespo-Villanueva Adrián,
Meis Sandrina,
Gies Hermann,
Bikondoa OierORCID
Abstract
The surface structure of fluoroapatite (0001) (FAp0001) under quasi-dry and humid conditions has been probed with surface X-ray diffraction (SXRD). Lateral and perpendicular atomic relaxations corresponding to the FAp0001 termination before and after H2O exposure and the location of the adsorbed water molecules have been determined from experimental analysis of the crystal truncation rod (CTR) intensities. The surface under dry conditions exhibits a bulk termination with relaxations in the outermost atomic layers. The hydrated surface is formed by a disordered partially occupied H2O layer containing one water molecule (33% surface coverage) adsorbed at each of the three surface Ca atoms, and is coupled with one OH group randomly bonded to each of the three topmost P atoms with a 33% surface coverage.
Funder
European Regional Development Fund
Engineering and Physical Sciences Research Council
Spanish Ministry of Education and Science
Publisher
International Union of Crystallography (IUCr)
Subject
Materials Chemistry,Metals and Alloys,Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials
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