Introduction of boron in hydroxyapatite: synthesis and structural characterization

• Published in: Journal of alloys and compounds 2002-02, Vol.333 (1), p.62-71
• Main Authors: Ternane, R., Cohen-Adad, M.Th, Panczer, G., Goutaudier, C., Kbir-Ariguib, N., Trabelsi-Ayedi, M., Florian, P., Massiot, D.
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Inelastic light scattering; Infrared and raman spectra and scattering; Inorganic compounds; Inorganic materials; Laser materials; Material chemistry; Nuclear resonances; Optical materials; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optics; Other nonmetallic inorganics; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(01)01558-4

Apatites doped with rare-earth ions have been extensively studied due to their potential applications as phosphors or laser hosts. The structure of apatite is based on a network of only tetrahedral PO 4 groups. When boron is added, phosphate and OH groups would be partially substituted by borate groups and new calcium borohydroxyapatite with nominal stoichiometry Ca 10 PO 4 6−x BO 3 x BO 3 y BO 2 z OH 2−3y−z is proposed. When P/B ratio=7.22, boron atoms are totally introduced in the apatitic lattice, but from P/B=11 samples are biphased borohydroxyapatite and Ca(OH) 2 and when P/B is lower than 7.22, Ca 3(BO 3) 2 is also observed. The infra-red (IR) and Raman spectroscopy and 11B MAS (magical angle spinning)–NMR experiments prove that boron is introduced as two-fold coordinated boron BO − 2 in the channels of the apatitic structure and as triangular BO 3− 3groups substituting PO 4 and OH groups leading to a AB-type borohydroxyapatite. A comparison with a free boron hydroxyapatite shows that P and proton sites are split into several sites in the substituted compounds.