Pressure and temperature dependence of the structure of liquid arsenic and antimony

The structure of liquid As and liquid Sb have been measured under high pressure and high temperature by energy-dispersive X-ray diffraction method. The coordination number of liquid As was found to be 3.5 at 1.0GPa, and it showed an increase to around 6 at 10GPa. The change suggests a crossover from a A7-like to a simple-cubic-like structure occurs at this pressure range. Further compression up to 17.1GPa has been made and the structural change in all pressure region is discussed. The pressure dependence of the structure factor, pair-distribution function, and the coordination number for liquid Sb are reported.