High pressure X-ray diffraction study of tungsten disulfide

Synchrotron X-ray diffraction was used in conjunction with a diamond anvil cell to investigate the properties of tungsten disulfide (WS2) to 25.5 GPa at room temperature. No pressure medium was used to generate hydrostatic pressure. No phase transformation was observed in the pressure range studied. By fitting the pressure-volume data to the third-order Birch-Murnaghan equation of state, the bulk modulus was determined to be K0T=61±1 GPa with its pressure derivative K′0T=9.0±0.3. It is also found that the c-direction of the hexagonal structure is much more compressible than the a-direction.