High-energy synchrotron X-ray diffraction study of high-temperature levitated liquids

High-energy x-ray diffraction experiments were performed on amorphous silica at the high temperatures at high-energy x-ray diffraction beamline BL04B2 of SPring-8. The conical nozzle levitation system was integrated with a two-axis diffractometer for glass, liquid, and amorphous materials. The incident photon energy was 113.3 keV, and diffraction patterns were measured in a transmission geometry at 1330°C The magnitude of the first sharp diffraction peak (FSDP, Q ∼ 1.525 Å) in the total structure factor, S(Q), of amorphous silica significantly decreased at 1330°C, which has not been observed at temperatures lower than the glass transition temperature (T _g=1180°C) in previous studies. Total correlation function, T(r), suggested that the 2nd Si-O correlation is disordered due to the increased thermal-vibrations of Si-O tetrahedra. The structural model obtained by reverse Monte Calro modelling suggested that the ring statistics is unchanged at high temperature, whereas SiO₄ tetrahedra are distorted.