TY - JOUR A1 - Quillard, S. A1 - Mellier, C. A1 - Gildenhaar, Renate A1 - Hervelin, J. A1 - Deniard, P. A1 - Berger, Georg A1 - Bouler, J.-M. T1 - Raman and infrared studies of substituted ß-TCP N2 - Several substituted β-tricalcium phosphates have been prepared with different cations (monovalent, divalent and trivalent) and at various levels of substitution. Structural investigations have proved that fewer than ~10% wt substitution, the substituted compounds are isostructural to β-TCP, leading to solid solutions. These samples have been characterized by infrared and Raman spectroscopies. The vibrational spectra show mainly the bands related to the vibrations of PO43- tetrahedrons present in the structure. As Raman scattering and infrared absorption are local probes, the bands are sensitive to the local environment of the distinct tetrahedrons, related to the site of substitution and to the nature of the cations. KW - Tricalcium phosphates KW - Ionic substitution KW - Vibrational spectroscopies PY - 2012 U6 - https://doi.org/10.4028/www.scientific.net/KEM.493-494.225 SN - 1013-9826 VL - 493-494 SP - 225 EP - 230 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-24954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quillard, S. A1 - Paris, M. A1 - Deniard, P. A1 - Gildenhaar, Renate A1 - Berger, Georg A1 - Obadia, L. A1 - Bouler, J.-M. T1 - Structural and spectroscopic characterization of a series of potassium- and/or sodium-substituted beta-tricalcium phosphate N2 - In this paper, we report X-ray diffraction investigations as well as Raman and solid-state 31P and 23Na magic angle spinning nuclear magnetic resonance (NMR) characterization of three series of calcium orthophosphates. The general formulae of the studied compounds are Ca10.5-x/2Mx(PO4)7, where M = K or Na and x = 0, 0.25, 0.50, 0.75, 1.0; and Ca10KxNa1-x(PO4)7, where x = 0, 0.25, 0.5, 0.75, 1.0. These calcium orthophosphates are found to be isostructural with β-tricalcium phosphate (β-TCP, Ca3(PO4)2) with the substitution of some calcium sites by potassium and/or sodium cations. The unit cell parameters vary continuously with the level of substitution, a characteristic of these solid solutions. The Raman spectra show the different vibrational bands of the phosphate groups PO4, while the NMR chemical shifts are sensitive to the non-equivalent phosphorus and sodium ions present in these substituted samples. As both Raman and NMR spectroscopies are local probes, they offer tools to distinguish between these different phosphorus and phosphate groups, according to their structural site and local environment, especially the type of cation substituent. A convenient decomposition of the Raman and NMR spectra into Gaussian–Lorentzian components leads us to propose an assignment of the main observed bands of these substituted β-TCPs. KW - Bioceramics KW - Tricalcium phosphate KW - X-ray diffraction KW - Raman spectroscopy KW - Solid-state NMR spectroscopy PY - 2011 U6 - https://doi.org/10.1016/j.actbio.2010.12.016 SN - 1742-7061 VL - 7 IS - 4 SP - 1844 EP - 1852 PB - Elsevier CY - Amsterdam AN - OPUS4-23405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -