Structural description of pressure-induced amorphization in ZrW2O8
D A Keen, A L Goodwin, M G Tucker, M T Dove, J S O Evans,
W A Crichton and M Brunelli
Phys Rev Lett 98, 225501 (2007)
ZrW2O8 undergoes a high-pressure amorphization transition above 1.5 GPa to a phase which is recoverable to ambient conditions. Reverse Monte Carlo modeling of neutron and x-ray total scattering data from ZrW2O8 recovered from ∼4 GPa shows that the large increase in density on pressurizing ZrW2O8 is accommodated within the structure by increased bonding between the WO4 tetrahedra. This increases the tungsten coordination; changes to the ZrO6 octahedral environment are not required. This densified crystal-based model, which contains significant local disorder within a distorted periodic structure, is also in reasonable agreement with x-ray and neutron total scattering data measured in situ at high pressure.