Abstract
C a 2.90 M e 0.10 2 + ( P O 4 ) 2 (with Me = Mn, Ni, Cu) β-tricalcium phosphate (TCP) powders were synthesized by solid-state reaction at T = 1200 °C and investigated by means of a combination of scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, and luminescence spectroscopy. SEM morphological analysis showed the run products to consist of sub spherical microcrystalline aggregates, while EDS semi-quantitative analysis confirmed the nominal Ca/Me composition. The unit cell and the space group were determined by X-ray powder diffraction data showing that all the compounds crystallize in the rhombohedral R3c whitlockite-type structure, with the following unit cell constants: a = b = 10.41014(19) Å, c = 37.2984(13) Å, and cell volume V = 3500.53(15) Å3 (Mn); a = b = 10.39447(10) Å, c = 37.2901(8) Å; V = 3489.22(9) Å3 (Ni); a = b = 10.40764(8) Å, c = 37.3158(6) Å, V = 3500.48(7) Å3 (Cu). The investigation was completed with the structural refinement by the Rietveld method. The FTIR spectra are similar to those of the end-member Ca β-tricalcium phosphate (TCP), in agreement with the structure determination, and show minor band shifts of the (PO4) modes with the increasing size of the replacing Me2+ cation. Luminescence spectra and decay curves revealed significant luminescence properties for Mn and Cu phases.
Highlights
Calcium phosphate materials have been largely employed in biomedical applications, such as coatings of components of bone and teeth used in implantology
scanning electron microscopy (SEM) images show that the synthesized tricalcium phosphate (TCP) compounds crystallize with morphologies slightly different from phase to phase
Ni-TCP consists of crystallites with dimensions ranging from 5 up to 10 μm (Figure 1c), displaying subspherical habit; those with larger sizes assemble into porous aggregates with irregular shape
Summary
Calcium phosphate materials have been largely employed in biomedical applications, such as coatings of components of bone and teeth used in implantology. Ca10 (PO4 ) (OH) hydroxyapatite (HAp), the synthetic counterpart is poorly resorbed in the body: For this reason, many calcium phosphates, more resorbable and capable of inducing a better bone regeneration, have been preferred to HAp for biomedical applications [2]. Like HAp that allows noticeable substitutions in both cationic and anionic sites of its structure [4], synthetic β-TCP is well known to be flexible enough for a wide number of cationic substitutions without significant lattice distortions [5] This gives rise to a large number of products employed in biomedical sciences, for grafts [6] or coatings [7] in bone repairing and in teeth implants [8], or in optical applications due to their excellent luminescence properties when doped with Mn [9] or rare earth elements (RE) [10,11]. Β-TCP is widely investigated because of its close structural relationship with whitlockite Ca18 Mg2 (PO4 ) (PO3 OH)2 [12] and merrillite Ca18 Na2 Mg2 (PO4 ) (found in Moon rocks and meteorites) minerals [13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
