High-pressure neutron experiments on SiO glass using J-PARC high-pressure neutron diffractometer PLANET

Hattori, Takanori   ; Yagafarov, O.*; Katayama, Yoshinori; Sano, Asami   ; Saito, Hiroyuki; Chiba, Ayano*; Inamura, Yasuhiro  ; Suzuya, Kentaro; Otomo, Toshiya*

SiO glass consists of SiO tetrahedra. This glass is easily densified by applying pressure, due to its relatively sparse network ring formed by the linkage of tetrahedra. The density increase amounts to 20% by room temperature compression to 8 GPa. This increase is, however, released after decompression because of insufficient structural relaxation. On the other hand, the heating at high pressures promotes the structural relaxation, resulting in permanent densification of 20% at most. The mechanism of this densification has been investigated so far, but the microscopic origin is still to be revealed. So, we performed in-situ high-pressure neutron experiments at newly constructed high-pressure neutron beamline PLANET in J-PARC. We will discuss the origin of the reversibility in the densification.