Repeatable photoinduced insulator-to-metal transition in yttrium oxyhydride epitaxial thin films

Komatsu, Yuya*; Shimizu, Ryota*; Sato, Ryuhei*; Wilde, M.*; Nishio, Kazunori*; Katase, Takayoshi*; Matsumura, Daiju; Saito, Hiroyuki*; Miyauchi, Masahiro*; Adelman, J. R.*; et al.

Chemistry of Materials, 34(8), p.3616 - 3623, 2022/04

https://doi.org/10.1021/acs.chemmater.1c03450

Investigation on gasochromic properties of tungsten oxides using ion irradiation

Takano, Katsuyoshi; Inoue, Aichi; Yamamoto, Shunya; Sugimoto, Masaki; Miyashita, Atsumi; Yoshikawa, Masahito; Sugiyama, Akira; Nagata, Shinji*

no journal, , 

To improve the gasochromic coloration, ion irradiations with He at 350 keV for tungsten tri-oxide (WO) films were performed. The coloration was improved by the irradiations with the fluence of 110 ions/sm, as that the extent of coloration level is 7.5 times lager than that of non-irradiated film. In the irradiated films, it is estimated from the fitting analysis for W 4 photoemission spectra that 20 % of the oxygen in the film defects due to the irradiation. And then, it is found from X-ray diffraction measurements the distance of (100) planes in monoclinic phase is expanded to 2 %. The improvement of the gasochromic coloration of the irradiated WO films relates to the increment of oxygen defects induced by the irradiation, through the distortion of crystal structure.

Reconstruction of the paleoclimate at the time of formation of fluvial terraces based on phytolith analysis; An Example in the Kaburakawa river basin, Kanto, Japan

Tajikara, Masayoshi; Yasue, Kenichi; Sugiyama, Shinji*; Takada, Keita*; Kato, Takayuki*; Sugai, Toshihiko; Morita, Yoshimune*; Furusawa, Akira*

no journal, , 

no abstracts in English

Depositional sequence of the Post-LGM incised-valley fill controlled by seismic crustal deformation and large-scale lahars; An Example of SKM core obtained from the Sukumo coastal lowland along the Nankai Trough, Japan

Nanayama, Futoshi*; Yamaguchi, Tatsuhiko*; Nakanishi, Toshimichi; Tsuji, Tomohiro*; Ikeda, Michiharu*; Kondo, Yasuo*; Miwa, Michiko*; Sugiyama, Shinji*; Kimura, Kazunari*

no journal, , 

The characteristics of the post-LGM incised valley fills and the depositional sequence were examined the SKM core collected in the Sukumo coastal lowland, where is expected to huge seismic subsidence due to the Nankai Trough great earthquakes. Our sedimentological, radiocarbon dating and paleoenvironmental results are as bellows. Sediments of the SKM core clearly show a succession influenced by post-glacial sea level change. The Matsuda River incised valley was formed in LGM and filled by fluvial sand and gravels in late Pleistocene. After the postglacial transgression, sea level reached -30 m (a.s.l.) at 9.8 ka and the incised valley changed to an estuary environment. The sea level continued to rise and it became an inner bay mud bottom environment, and reaching a maximum water depth was at 7.5 ka. The 7.3 ka Kikai caldera eruption in southern Kyushu caused heavy K-Ah ash fall in southwestern Shikoku, and then large-scale lahars frequently occurred immediately after the ash fall because of the vicinity of volcanic source. After ash fall, the K-Ah secondary sediments rapidly deposited on the inner bay environment and caused forced regression. After 7.0 ka, the growth of the delta became active ahead of the other regions, which may be due to the large K-Ah ash fall. At 5 ka, the sea level reached + 2.5 m (a.s.l.) estimated by the Sukumo midden and this altitude is recognized as the Holocene marine limit in this area. The information on relative sea level change during the past 10000 years has revealed that the Sukumo Bay area has not subsided due to seismic crustal deformation.