With the recent opening of the Xpress beamline [1] the high pressure (HP) diffraction community have a dedicated experimental set up at the Elettra synchrotron facility. Xpress is part of a scientific partnership between India and Italy under a project administered through the IISc Bangalore, comprising also the macromolecular X-ray diffraction beamline XRD2. Both beamlines utilize the radiation from a 49 poles, 3.6 Tesla Superconducting Wiggler, Xpress employing the leftmost part of the wiggler fan to produce a 25 keV monochromatic X-ray beam focused on a large area detector (MAR345) for data acquisition in angle dispersive mode. This configuration allows powder diffraction experiments to be performed under HP using a variety of diamond anvil cells (DAC) and comprises an online ruby fluorescence spectrometer. The beamline station is equipped with state of the art facilities for HP manipulation: high magnification long working distance microscope, precision microdriller, automatic pneumatic pressure controller, etc. In front of the detector a precision stage enables an easy switching between the pressure monitoring ruby fluorescence and the diffraction data collection using finite size (tens of microns in diameter) monochromatic X-ray beam. A commercial gas loading system, an in house developed cryogenic gas loader (for Ar, N2, CO2, etc.) and HP diffraction measurements at low temperature using a N2 cryo stream are currently in the advanced stages of commissioning. Very recently, single crystal (SC) XRD measurements under HP were successfully commissioned in a membrane DAC; once further improvements will be implemented, HP-single crystal will be available for the users.
We will present recent scientific highlights of the beamline activity performed on both powder and SC under HP, such as pressure-induced amorphisation, pressure-induced phase transition, insertions and synthesis of new nanocomposites.
Xpress developments are in progress, perspectives for a near future are powder and single crystal diffraction under HP (up to megabar pressures) together with variable temperatures from few to several hundred Kelvins.
Next proposal submission deadline is on September 16th, 2019.
[1] https://www.elettra.trieste.it/elettra-beamlines/xpress.html