Inorganic Chemistry, Vol.50, No.17, 8252-8260, 2011
Characterization and Properties of Novel Gallium-Doped Calcium Phosphate Ceramics
Addition of a gallium (Ga) precursor in the typical reaction protocols used for the preparation of beta-tricalcium phosphate (beta-TCP) led to novel Ga-doped beta-TCP ceramics with rhombohedral structures (R3c space group). From the refinement of their X-ray diffraction patterns, it was found that the incorporation of Ga in the beta-TCP network occurs by substitution of one of the five calcium (Ca) sites, while occupation of another Ca site decreases in inverse proportion to the Ga content in the structure. The Ga local environment and the modification of the phosphorus environments due to the Ga/Ca substitution in Ga-doped beta-TCP compounds are probed using P-31 and Ga-71 magic-angle spinning NMR. A decrease of the unit cell volume is observed with increasing Ga content, together with improved mechanical properties. Indeed, the compressive strength of these new bioceramics is enhanced in direct proportion of the Ga content, up to a 2.6-fold increase as compared to pure beta-TCP.