Synthesis and structural characterization of strontium- and magnesium-co-substituted β-tricalcium phosphate

The synthesis of five different Sr2+- and Mg2+-co-substituted β-tricalcium phosphate (β-TCP) has been obtained by heating the calcium-deficient apatites above 800 °C. With the investigated concentrations of Sr2+ and Mg2+ from the present study, no additional phases other than β-TCP have been detected. The synthesized powders have been characterized by X-ray diffraction, Fourier transform infrared spectrometry, elemental analysis and Rietveld refinement studies. The co-substitution of Sr2+ and Mg2+ in the β-TCP has resulted in the formation of crystalline β-TCP at hexagonal setting (space group R3c). The reduction of lattice a- and c-axis parameters with the combined substitution of Sr2+ and Mg2+ in the β-TCP has been found evident from the present results. Sr2+ has been found occupying the Ca(1,2,3,4) sites and Mg2+ was found at the sixfold coordinated Ca(5) site of β-TCP structure.