PRESSURE-INDUCED STRUCTURAL-CHANGE OF LIQUID CESIUM

X-ray diffraction for liquid cesium has been measured at pressures to 4.3 GPa, at which V/V0 is 0.4, by using synchrotron radiation. Pressure dependences of static structure factor S(Q) and pair distribution function g(r) were obtained. At about 2 GPa, a transition from bcc-like structure to fcc-like one in liquid state is suggested. Remarkable changes in S(Q) and g(r) exhibit another transition at pressure between 3 GPa and 4 GPa to a denser structure. The former transition is discussed in comparison with the pressure-induced phase transition in crystal. And the latter is discussed in relation to the 6s-5d electronic transition and the melting curve maxima. © 1990.