High-pressure X-ray diffraction study on alpha-PbF2

The high-pressure behaviour of alpha-PbF2 was investigated by angular-dispersive synchrotron X-ray powder diffraction up to 6.55(8) GPa. The fit of a third-order Birch-Murnaghan equation-of-state gave the volume at zero pressure Vo=194.14(4) Angstrom**3 and the bulk modulus b=47.0(6) GPa with the pressure derivative b´=7.9(4). The continuous-symmetry-measure approach has been used for the quantification of the distortion of the coordination polyhedron in alpha-PbF2 revealing an increasing distortion with pressure