Compression of CsCl and CsBr in the megabar range

ABSTRACT

The quasi-hydrostatic compression of cesium chloride and cesium bromide has been measured with X-ray diffraction up to 141 GPa at 300 K. A cubic to orthorhombic $Pm\overline{3}m\to Pmma$ transition, with a ≥10% distortion of lattice parameters, is evidenced in CsBr around 60 GPa. A smaller distortion (∼1.5%) appears in CsCl at the same pressure, followed by a likely transition to a lower symmetry phase which starts at 134 GPa. P−V compression curves yield equation of state parameters in line with those of other B2 alkali halides.

KEYWORDS:

• Diamond anvil cell
• phase transformations
• cesium halides

Acknowledgments

We acknowledge synchrotron ESRF for the provision of beamtime (proposal HC-2470). We thank Florent Occelli for his help with samples loading.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by European Synchrotron Radiation Facility [HC-2470].