High-pressure phase transformation and the equation of state of SrSe

Abstract

The crystalline structure of the heavy alkaline earth chalcogenide SrSe was studied at high pressure by x-ray diffraction using a synchrotron source. The NaCl-type (B1) structure of SrSe was found to be stable on loading to 14.2 GPa where the CsCl-type (B2) structure was evidenced with a 10.7% decrease in relative atomic volume. The B2 phase of SrSe persists to 40 GPa, the highest pressure attempted in the experiments. The B1-B2 phase transition was found to be reversible with small hysteresis. The bulk modulus and its pressure derivative were determined for both phases. Systematic behavior among the strontium chalcogenides is discussed.