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Mechanical properties of sulfide glasses in all-solid-state batteries

Kato, Atsutaka; Nose, Masashi; Yamamoto, Mirai; Sakuda, Atsushi; Hayashi, Akitoshi; Tatsumisago, Masahiro

Understanding diffraction patterns of glassy, liquid and amorphous materials via persistent homology analyses

Yohei ONODERA, Shinji KOHARA, Shuta TAHARA, Atsunobu MASUNO, Hiroyuki INOUE, Motoki SHIGA, Akihiko HIRATA, Koichi TSUCHIYA, Yasuaki HIRAOKA, ...

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published : vol. 131, no. 3, March 2023
Tetsuya Yamada, Kaito Kanda, Yasuko Yanagida, Gen Mayanagi, Jumpei Washio and Nobuhiro Takahashi
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This study addresses the advantages of using a lanthanum fluoride (LaF3) nanocrystals-based fluoride ion sensor. We propose a method that enables the preparation of fluoride ion-selective LaF3 nanocrystals at low temperatures (less than 80 °C) in contrast to the conventional method, wherein high temperatures (1000 °C and above) are required for preparing a single-crystal LaF3. An LaF3 nanocrystal with a diameter below 5 nm in the (001) plane was synthesized and subsequently deposited on a Ti electrode. The sensor exhibited a selective response to fluoride ions. This process does not require high-temperature and vacuum equipment and conditions, thus enabling easy production of fluoride ion sensors.
Full Paper
published : vol. 131, no. 3, March 2023
Shingo Machida, Kei Maeda, Ken-ichi Katsumata and Atsuo Yasumori
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Microstructural control of MgO–Al2O3–SiO2 (MAS) glass-ceramic (GC) with precipitated enstatite (MgSiO3) in the 0.68–12 µm range from a parent glass having one composition was achieved by using titanium oxides with varying particle sizes and crystallinities as nucleation agents. Specifically, compared with the MAS-GC prepared using TiO2 with 50–200 nm and relative high crystallinity (TiO2-L-H), the MAS-GC prepared by mixing TiO2-L-H with TiO2 having single nanometer size and relative low crystallinity displayed an increase in the average crystal particle size from 6.0 to 12 µm with the preservation of volume fraction. In addition, compared with the MAS-GC prepared using TiO2-L-H, the MAS-GC prepared by TiO2 having single nanometer size and relative high crystallinity exhibited a decrease in the average size of crystal particle from 6.0 to 0. 68 µm with a decrease in the volume fraction from 76 to 67 %. Therefore, these results indicated that the particle size and crystallinity of the raw glass materials are key parameters for controlling the microstructure of GCs.
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published : vol. 131, no. 3, March 2023
Mingkai Zhou and Xuexiang Ge
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Foamed ceramic is a novel lightweight wall material combining high strength, low density, and excellent thermal insulation. This study used coal bottom ash (CBA) to fabricate microporous foamed ceramics by the high-temperature foaming method. The CBA content and heating rate effects on the bulk density, compressive strength, pore structure, and phase components of foamed ceramics were systematically investigated. The results demonstrate that using CBA in foamed ceramics can effectively improve the green body foaming capacity. With the increased CBA content, the bulk density of foamed ceramics dropped, while the average pore size and shape factor increased, jointly reducing the compressive strength. Meanwhile, the quartz phase content decreased, and the mullite phase appeared gradually. The transition of the main crystalline phase from MgAl2O4 to Mg0.7Fe0.23Al1.97O4 with the increased CBA content gave rise to a change in the color of the foamed ceramic. The elevation in the heating rate can improve the foaming ability of the green body, contributing to increased porosity. However, the rapid heating rate of 10 °C/min results in an uneven pore size distribution in the foamed ceramics containing more than 70 wt % CBA. It increases the temperature difference in the sample, promoting a stratified distribution of pore size in samples with a CBA content of less than 30 wt %.
Express Letter
published : vol. 131, no. 3, March 2023
Hiromasa Kuroda, Junichi Tatami, Motoyuki Iijima and Takuma Takahashi
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In the wet forming of ceramics, it is critical to control the cracking and deformation of the ceramic slurry during the drying process. This necessitates a comprehensive understanding of the changes in the internal structure of the slurry during the drying process using a high-resolution technique that enables direct and high speed observation. In this study, a combined system of optical coherence tomography (OCT) and thermogravimetry (TG) was developed for the operando observation of the evolution of the internal structure of a drying SiO2 slurry. In the early stages of drying, the OCT signal intensity changed significantly owing to the Brownian motion of the SiO2 particles in the slurry. The slurry was found to shrink as it dried and then lose its fluidity, and the ceramic particles were found to agglomerate from the surface. In the final stages of drying, localized dry regions developed in the vicinity of the slurry surface and expanded with drying. Crack formation was also observed in a part of the localized dry regions. Therefore, crack formation was attributed to inhomogeneous drying-induced shrinkage and stress generated in the drying object during the progression of localized drying. The novel operando observation technique using combined OCT-TG is successfully demonstrated to be an effective approach for understanding the internal structural changes in opaque slurries during their drying.