High-pressure equation of state of cesium fluoride to 120 GPa

Abstract

We have performed a high pressure synchrotron X-ray diffraction study of the ionic salt, cesium fluoride (CsF), up to 120 GPa. We observed the B1 → B2 phase transition near 5 GPa as previously reported. Beyond this pressure, no phase transitions were determined to have occurred up to the highest pressure studied. Unit cell data were calculated from the known B2 (CsCl) structure for all of the pressures studied above 5 GPa, and an equation of state (EOS) was fit to the data using a 3rd order Birch–Murnaghan equation in this phase. Density Functional Theory (DFT) was also employed to compute an EOS for comparison purposes. Our experimental results agreed very well with both sets of the predicted EOS.