Synchrotron radiation studies on pressure-induced structural changes in liquids and glasses

Katayama, Yoshinori; Inamura, Yasuhiro

Combination of synchrotron radiation sources and large volume presses enable us to make in-situ observations of structural change in liquids and glasses at high pressures up to several GPa and high temperatures up to 1500K. A number of methods, X-ray diffraction, XAFS, density measurement by means of X-ray absorption, viscosity measurements by means of radiography, are now applicable for this purpose. We have systematically studied elemental liquid and found that a characteristic structural change occurs in a narrow pressure-temperature range in liquid selenium. Moreover we have found a sudden structural change in liquid phosphorus. Experimental results on phosphorus support a view that the change is a first-order liquid-liquid transition. In the talk, results of current attempt to detect sudden structural change in silica glass will be presented. A preliminary result of X-ray diffraction study on liquid water under high-pressure will be also reported.