fulltext.study @t Gmail

Rietveld structure refinement of precipitated carbonate apatite using neutron diffraction data

Paper ID Volume ID Publish Year Pages File Format Full-Text
13142 832 2004 9 PDF Available
Title
Rietveld structure refinement of precipitated carbonate apatite using neutron diffraction data
Abstract

X-ray and time of flight neutron diffraction data, FTIR and MAS-NMR spectra, and ICP-AES and carbonate analyses have been collected from a sodium-containing carbonate apatite (CO3 content 12.5(7) wt%). A structural model based on Holly Springs hydroxyapatite without CO32− ions showed an apparent reduction in the PO4 tetrahedral volume which is ascribed to CO32− replacing PO43− ions in the lattice. Four structural models from the literature with the CO32− ion explicitly modelled were fitted to the neutron diffraction data by the Rietveld method.The best fit was obtained with the CO32− ion in disorder between the mirror symmetry related faces of a vacant PO43− site and with the normal to the plane of the CO32− ion at ∼30° to the c-axis. This angle is consistent with results from previous polarised IR measurements on single crystals of francolite (a fluorocarbonate apatite) and human dental enamel. Further refinement of the model revealed a hitherto unknown atom site close to the unit cell origin, (possibly a water molecule). The refined hexagonal unit cell parameters from the neutron diffraction data were a=9.3446(3) Å and c=6.9199(4) Å.

Keywords
Apatite structure; XRD; Neutron diffraction; Rietveld refinement; Francolite; Carbonate apatite
First Page Preview
Rietveld structure refinement of precipitated carbonate apatite using neutron diffraction data
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 25, Issue 11, May 2004, Pages 2205–2213
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us