X-ray diffraction study of molybdenum diselenide to 35.9 GPa

In situ high-pressure angle dispersive synchrotron X-ray diffraction studies of molybdenum diselenide (MoSe2) were carried out in a diamond-anvil cell to 35.9 GPa. No evidence of a phase transformation was observed in the pressure range. By fitting the pressure-volume data to the third-order Birch-Murnaghan equation of state, the bulk modulus, K-OT, was determined to be 45.7 +/- 0.3 GPa with its pressure derivative, K'(OT), being 11.6 +/- 0.1. It was found that the c-axis decreased linearly with pressure at a slope of -0.1593 when pressures were lower than 10 GPa. It showed different linear decrease with the slope of a -0.0236 at pressures higher than 10 GPa. (C) 2008 Elsevier Ltd. All rights reserved.