摘要
The high pressure induced phase transition in rhenium diselenides (ReSe <sub>2</sub> ) and gold-doped rhenium diselenides (Au-ReSe <sub>2</sub> ) at ambient temperature have been investigated using angular-dispersive x-ray diffraction (ADXRD) under high pressure up to around 10.50 and 9.98 GPa, respectively. In situ ADXRD measurements found that the phase transition pressures of ReSe <sub>2</sub> and Au-ReSe <sub>2</sub> began at 9.98 and 8.52 GPa, respectively. Compressibilities analysis shows the relationship of along c-axis > along a-axis > along b-axis. The linear compressibility of the pressure dependence of α, β, and γ of ReSe <sub>2</sub> shows that a phase transition can be related to a counterclockwise rotational trend of the selenium atoms around the chain of Re <sub>4</sub> atoms during the decrease of the c-axis distance by a combination of stresses due to the bending effect of α and stretching effect of β. The cause of the reduction of the phase transition pressure of Au-ReSe <sub>2</sub> is attributed mainly to a structural distortion as evidenced by the observation of a weak clockwise rotational trend of Se atoms around the chain of Re <sub>4</sub> atoms in the pressure range 3.99-4.99 GPa which subsequently reversed to counterclockwise rotation under higher pressure. © 2012 American Institute of Physics.