Influence of magnesium doping on the phase transformation temperature of beta-TCP ceramics examined by Rietveld refinement.

The influence of Mg doping in Ca(3)(PO(4))(2) on the transformation temperature of beta-tricalcium phosphate (beta-TCP) to alpha-tricalcium phosphate (alpha-TCP) was examined. A maximum substitution by 14 mol% of Mg(2+) on Ca(2+) sites in the beta-TCP structure was determined for powders calcinated at 1025+/-10 degrees C. X-ray powder diffraction analysis (XRPD) in combination with Rietveld method (TOPAS 2.1) was employed for quantitative phase analysis and structural refinement. The synthesized and characterized Mg-doped samples were sintered in air atmosphere in a vertical tube furnace at suitable temperatures ranging from 1460 to 1680 degrees C and subsequently quenched to room temperature, in order to stabilize alpha-TCP. The beta to alpha transformation temperatures were determined by differential temperature analysis and XRPD analysis.