Structural characterization of iodate and carbonate substituted calcium hydroxyapatites: insights from XRD, SEM, and TEM
Abstract
This study investigates the structure and microstructure of hydroxyapatite substituted with iodate (IO3−) and/or carbonate (CO32−) ions, within the context of long‐lived radionuclide waste conditioning. The role of the synthesis protocol, “reverse” or “direct” precipitation from aqueous solution, as well as the nature and amount of substituted anions on the structure and microstructure of hydroxyapatite samples, was evaluated using XRD, SEM, and HRTEM. The anisotropic crystallite shape assessed by HRTEM analyses was taken into account for the Rietveld refinements of the XRD patterns. Considering the reverse synthesis protocol, these refinements revealed the formation of a single hydroxyapatite phase. Despite the use of long counting times, no crystalline secondary phases were detected by XRD, regardless of the nature and amount of the substituting anions. Iodate ions substituting for A sites tend to expand the lattice, while carbonate ions located in B sites induce lattice contraction. Clearly, the influence of iodate substitution on the structural modifications is lower than that of carbonate substitution. Moreover, co‐substitution seems to modify the incorporation mode of iodate ions within the structure. The intended application of this work requires studying high substitution rates, thereby addressing gaps in the literature regarding the structural evolution of hydroxyapatite with increasing substitution rates. In this study, substitution levels reached up to 15.4 wt.% for iodate mono‐substitutions, 11.9 wt.% for carbonate mono‐substitutions, and approximately 20 wt.% for combined iodate and carbonate ions co‐substitutions.
Related
- Effects of Pretreatment on the Isotopic Composition of Structural Carbonate in Ray‐Finned Fish Teeth
- Synthesis and Vibrational Identification of the Uranyl Peroxodicarbonato [UO2(O2)(CO3)2]4–: Insights into Peroxide-Carbonate Bonding from 18O Labeling, DFT, and QTAIM Analysis
- Synthesis, characterization, and catalytic performance of cobalt and nickel-substituted polyoxometalates organic-inorganic nanohybrids
- Temperature dependent magnetic and structural properties of Al substituted nanostructured hexaferrites with large coercive fields
- Correlation-Driven Singlet--Triplet Inversion and Optical Spectra of N-Substituted Phenalenyls: Insights from PPP-FCI and TDDFT
BibTeX
@article{audouard2026structural,
title = {{Structural characterization of iodate and carbonate substituted calcium hydroxyapatites: insights from XRD, SEM, and TEM}},
author = {Lisa Audouard and Marie‐noëlle de Noirfontaine and Mireille Courtial and Sandrine Tusseau-Nenez and Florian Aubrit and Olivier Dautain and Christèle Combes and Céline Cau Dit Coumes and Lionel Campayo},
journal = {Journal of the American Ceramic Society},
year = {2026},
month = aug,
doi = {10.1111/jace.71164},
url = {https://hal.science/hal-05739049v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Structural characterization of iodate and carbonate substituted calcium hydroxyapatites: insights from XRD, SEM, and TEM
AU - Lisa Audouard
AU - Marie‐noëlle de Noirfontaine
AU - Mireille Courtial
AU - Sandrine Tusseau-Nenez
AU - Florian Aubrit
AU - Olivier Dautain
AU - Christèle Combes
AU - Céline Cau Dit Coumes
AU - Lionel Campayo
PY - 2026
DA - 2026/08/28
JO - Journal of the American Ceramic Society
DO - 10.1111/jace.71164
UR - https://hal.science/hal-05739049v1
AB - This study investigates the structure and microstructure of hydroxyapatite substituted with iodate (IO_3^−) and/or carbonate (CO_3^2−) ions, within the context of long‐lived radionuclide waste conditioning. The role of the synthesis protocol, “reverse” or “direct” precipitation from aqueous solution, as well as the nature and amount of substituted anions on the structure and microstructure of hydroxyapatite samples, was evaluated using XRD, SEM, and HRTEM. The anisotropic crystallite shape assessed by HRTEM analyses was taken into account for the Rietveld refinements of the XRD patterns. Considering the reverse synthesis protocol, these refinements revealed the formation of a single hydroxyapatite phase. Despite the use of long counting times, no crystalline secondary phases were detected by XRD, regardless of the nature and amount of the substituting anions. Iodate ions substituting for A sites tend to expand the lattice, while carbonate ions located in B sites induce lattice contraction. Clearly, the influence of iodate substitution on the structural modifications is lower than that of carbonate substitution. Moreover, co‐substitution seems to modify the incorporation mode of iodate ions within the structure. The intended application of this work requires studying high substitution rates, thereby addressing gaps in the literature regarding the structural evolution of hydroxyapatite with increasing substitution rates. In this study, substitution levels reached up to 15.4 wt.% for iodate mono‐substitutions, 11.9 wt.% for carbonate mono‐substitutions, and approximately 20 wt.% for combined iodate and carbonate ions co‐substitutions.
SN - 0002-7820
SN - 1551-2916
ER -