48P1-05Structural Analysis of Densified SiO2 Glass Synthesized Under Extreme Conditions Using Quantum Beam Shuya Sato1,2, Masashi Miyakawa3,Takashi Taniguchi3, Koji Kimoto2, Yohei Onodera2, and Shinji Kohara2,1 1 Graduate School of Science and Technology, Tokyo University of Science 2 Center for Basic Research on Materials, National Institute for Materials Science (NIMS) 3 Research Center for Materials Nanoarchitectonics, National Institute for Materials Science (NIMS) [1] T. Negishi, K. Yamaguchi, NEW GLASS, 26, 11 (2011). [2] Y. Onodera, S. Kohara, P.S. Salmon et al., NPG Asia Mater., 12, 85 (2020). P1-06Investigation of the Formation of a Zirconium Oxide Crystal Nucleus in the Initial Nucleation Stage in Aluminosilicate Gdlass Yohei Onodera1, Yasuyuki Takimoto2, Hiroyuki Hijiya3, Qing Li3, Hiroo Tajiri4, Toshiaki Ina5,and Shinji Kohara1 1 Center for Basic Research on Materials, National Institute for Materials Science (NIMS) 2 Innovative Technology Laboratories, AGC, Inc 3 Materials Integration Laboratories, AGC, Inc 4 Scattering and Imaging Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8) 5 Spectroscopy Division, JASRI, SPring-8 [1] Y. Onodera et al., NPG Asia Mater., 16, 22 (2024). Poster Award NomineePoster Award NomineeGlassy SiO2 has been applied as a material for optical devices such as optical fibers. In particular, high refractive index and low dispersion glass containing tantalum has been used in camera lenses to achieve high performance such as wide-angle and high-magnification [1]. However, the rising prices of rare metals have created a need for alternate glass materials. In this study, we focused on hot-compressed SiO2 glass. The higher the temperatures and pressures during synthesis, the glass with high density and structural ordering related to refractive index and dispersion is recovered [2]. However, under these extreme conditions, it is difficult to recover the sample as a glass due to crystallization caused by inhomogeneous nucleation, and there are no reports of synthesis at 7.7 GPa above 1300 °C or higher. In this study, we synthesized densified SiO2 glass at higher pressures and higher temperatures by removing impurities on the sample surface that cause crystallization using surface treatment with hydrofluoric acid, and investigated the effects on the structure of SiO2 glass from diffraction and other experimental data. Glass-ceramics are composed of precipitated crystals and a glass matrix and are utilized in many industrial products. We conducted an X-ray multiscale analysis by combining diffraction, small-angle scattering, absorption, and anomalous scattering techniques to observe the structure of a commercially important ZrO2-doped lithium aluminosilicate glass-ceramic during its initial nucleation stage. Element-specific pair distribution function analysis using anomalous X-ray scattering (AXS) data showed the formation of edge-sharing between ZrOx polyhedra and (Si/Al)O4 tetrahedra during the initial nucleation stage. Furthermore, AXS data indicated that the local structure of the Zr4+ ions, which resembled a cubic or tetragonal ZrO2 crystalline phase, formed after 2 h of annealing the pristine glass. Therefore, the Zr-centric periodic structure surrounded by the (Si/Al)O4 tetrahedral network was potentially the initial crystal nucleus for the ZrO2-doped lithium aluminosilicate glass-ceramic[1].
元のページ ../index.html#48