X-ray diffraction study of -Ca3(PO4)2 at high pressure

The β -tricalcium phosphate phase, β - Ca 3 ( PO 4 ) 2 , has been studied at high pressures up to 15.4 GPa and room temperature in a diamond-anvil cell using angle-dispersive X-ray diffraction. No evidence of a phase transformation was observed in the present pressure range at 300 K. By fitting the pressure-volume data to a second-order Birch–Murnaghan equation of state, the bulk modulus, B 0 , was determined to be 79.5 ± 2.0 GPa.