Transformations in the intermediate-range structure of SiO glass under high pressure and temperature

Inamura, Yasuhiro*; Katayama, Yoshinori; Utsumi, Wataru; Funakoshi, Kenichi*

The temperature dependence of the X-ray structure factor for SiO glass was measured at several pressures up to 19.2 GPa. The position of the first sharp diffraction peak moved to a higher momentum transfer as the temperature increased in a specific pressure-temperature range. The intermediate range structure was thermally relaxed to a denser one. Around 7 GPa, the temperature-induced shift saturated and the crystallization temperature drastically increased. These results support the existence of a relatively stable high-pressure form of SiO glass. A sudden transformation was not observed.