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Physicochemical Properties and Structural Refinement of Strontium‐Lead Hydroxyapatites
Author(s) -
Badraoui Béchir,
Bigi Adriana,
Debbabi Mongi,
Gazzano Massimo,
Roveri Norberto,
Thouvenot René
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200207)2002:7<1864::aid-ejic1864>3.0.co;2-#
Subject(s) - hydroxyapatites , chemistry , strontium , lead (geology) , calcium , organic chemistry , geology , geomorphology
Continuous series of solid solutions of strontium and lead apatite Sr (10− x ) Pb x (PO 4 ) 6 (OH) 2 (0 ⩽ x ⩽ 10), synthesized in aqueous media have been investigated by X‐ray powder‐pattern fitting, 31 P MAS NMR and IR spectroscopy. The lattice dimensions and the IR frequencies of the solid solutions vary linearly with the atom% of lead. The results of the Rietveld analysis indicated a clear preference of lead for the M(2) site of the apatitic structure, so that in the samples with low Pb content it is almost exclusively found in the M(2) site. 31 P MAS NMR spectra at 162 MHz show a unique isotropic signal at δ iso between +2.9 (SrHA) and −0.7 ppm (PbHA). From the variation of δ iso with the phase composition it appears that 31 P shielding in these mixed apatites is essentially governed by the nature of the metal in the M(1) site. The qualitative variation of the chemical shift anisotropy of the PO 4 group agrees with the deviation from ideal T d symmetry shown by the Rietveld refinement analysis. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)