High-pressure synchrotron x-ray diffraction of Cs IV and Cs V

Using energy dispersive X-ray diffraction (EDX) at the superconducting wiggler beamline X17C of the National Synchrotron Light Source, we have performed new studies on the high pressure phases Cs IV and Cs V in a diamond-anvil cell to 38 GPa. For Cs IV, the data are consistent with the previously identified body centered tetragonal structure. However, for Cs V new diffraction lines are resolved that are inconsistent with any of the three previously proposed structures. This study demonstrates the suitability of synchrotron wiggler EDX techniques for studying complex structures such as Cs IV and V; by performing diffraction at the relatively high X-ray energies available from a wiggler, resolution superior to that available from either lower energy EDX studies or techniques using radiation from conventional sources can be obtained.