A pressure-induced amorphous phase transition in magnesium-substituted -tricalcium phosphate

Synchrotron-based X-ray diffraction was used to determine the equation of state and phase transition in magnesium-substituted β -tricalcium phosphate ( β -TCMP). It was observed that β -TCMP undergoes a phase transformation from a rhombohedral unit cell to an amorphous structure. This pressure-induced amorphization is reversible from ∼32 GPa under quasi-hydrostatic conditions and irreversible when quenched from ∼57 GPa in non-hydrostatic conditions. Based upon the quasi-hydrostatic equation of state, the bulk modulus for the crystalline phase of the material was calculated to be 80.6±3.1 GPa.