Springer Science and Business Media LLC Acta Medica Okayama 2041-1723 17 1 2026 Atomic imaging for hydrogen and boron aggregates in boron-doped diamond by spectro-photoelectron holography 3482 EN Hiroto Tomita Graduate School of Science and Technology, Nara Institute of Science and Technology Wataru Hosoda Research Institute for Interdisciplinary Science, Okayama University Takumi Taniguchi Research Institute for Interdisciplinary Science, Okayama University Hirokazu Fujiwara Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo Noriyuki Kataoka Research Institute for Interdisciplinary Science, Okayama University Taisuke Kageura Sensing Technology Research Institute, National Institute of Advanced Industrial Science and Technology Yoshihiko Takano Research Center for Materials Nanoarchitectonics, National Institute for Materials Science Hiroshi Kawarada Faculty of Science and Engineering, Waseda University Tamio Oguchi Center for Spintronics Research Network, The University of Osaka Takayoshi Yokoya Research Institute for Interdisciplinary Science, Okayama University Tomohiro Matsushita Graduate School of Science and Technology, Nara Institute of Science and Technology The electrical properties of diamond are modulated by impurity doping. Isolated substitutional boron atoms introduce holes; however, the fraction of electrically inactive boron atoms increases at higher doping concentrations. This has been attributed to boron aggregation and hydrogen passivation, although their structural identification based on atomic arrangement has yet to be experimentally verified. Here we show the origin of multiple chemical states in homoepitaxially grown boron-doped diamond thin films by analyzing the atomic environment of boron using spectro-photoelectron holography. Our analysis identifies boron dimers and boron-hydrogen complexes, with hydrogen occupying different atomic sites that give rise to distinct chemical shifts. These results suggest that hydrogen incorporation during growth leads to passivation of boron acceptors. We demonstrate that photoelectron holography serves as a promising tool for imaging hydrogen as well as determining the atomic sites of dopants. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2045-2322 15 1 2025 Local-structure insight into the improved superconducting properties of Pb-substituted La(O, F)BiS2: a photoelectron holography study 8366 EN Yajun Li Graduate School of Natural Science and Technology, Okayama University Yusuke Hashimoto Nara Institute of Science and Technology (NAIST) Noriyuki Kataoka Graduate School of Natural Science and Technology, Okayama University Zexu Sun Nara Institute of Science and Technology (NAIST) Sota Kawamura Nara Institute of Science and Technology (NAIST) Hiroto Tomita Nara Institute of Science and Technology (NAIST) Taro Setoguchi Graduate School of Natural Science and Technology, Okayama University Soichiro Takeuchi Nara Institute of Science and Technology (NAIST) Shunjo Koga Nara Institute of Science and Technology (NAIST) Kohei Yamagami Japan Synchrotron Radiation Research Institute (JASRI) Yoshinori Kotani Japan Synchrotron Radiation Research Institute (JASRI) Satoshi Demura Department of Physics, College of Science and Technology(CST), Nihon University Kanako Noguchi Tokyo University of Science Hideaki Sakata Tokyo University of Science Tomohiro Matsushita Nara Institute of Science and Technology (NAIST) Takanori Wakita Graduate School of Natural Science and Technology, Okayama University Yuji Muraoka Graduate School of Natural Science and Technology, Okayama University Takayoshi Yokoya Graduate School of Natural Science and Technology, Okayama University Pb-substituted La(O, F)BiS2 (Pb-LaOFBiS2) exhibits improved superconducting properties and a resistivity anomaly around 100 K that is attributed to a structural transition. We have performed temperature(T)-dependent photoelectron holography (PEH) to study dopant incorporation sites and the local structure change across the anomaly. The PEH study of Pb-LaOFBiS2 provided evidence for the dominant incorporation sites of Pb and F: Pb atoms are incorporated into the Bi sites and F atoms are incorporated into the O site. No remarkable difference in the local structures around Pb and Bi atoms was observed. Across the temperature of the resistivity anomaly (T*), photoelectron holograms of Bi 4f changed. Comparisons of holograms with those of non-substituted LaOFBiS2 sample, as well as simulated holograms, suggested that (1), above T*, the tetragonal structure of Pb-LaOFBiS2 is different from the tetragonal structure of LaOFBiS2 and (2), below T*, the tetragonal structure still remains in Pb-LaOFBiS2. We discuss a possible origin of the difference in the structure above T* and the implication of the result below T*, which are necessary ingredients to understand the physical properties of Pb-LaOFBiS2. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 0021-4922 62 12 2023 Photoelectron holographic evidence for the incorporation site of Se and suppressed atomic displacement of the conducting layer of La(O,F)BiSSe 125001 EN YaJun Li Engineering Research Center of Integrated Circuit Packaging and Testing, Ministry of Education, Tianshui Normal University ZeXu Sun Nara Institute of Science and Technology (NAIST) Noriyuki Kataoka Graduate School of Natural Science and Technology, Okayama University Taro Setoguchi Graduate School of Natural Science and Technology, Okayama University Yusuke Hashimoto Nara Institute of Science and Technology (NAIST) Soichiro Takeuchi Nara Institute of Science and Technology (NAIST) Shunjo Koga Nara Institute of Science and Technology (NAIST) Kazuhisa Hoshi Department of Physics, Tokyo Metropolitan University Yoshikazu Mizuguchi Department of Physics, Tokyo Metropolitan University Tomohiro Matsushita Nara Institute of Science and Technology (NAIST) Takanori Wakita Graduate School of Natural Science and Technology, Okayama University Yuji Muraoka Graduate School of Natural Science and Technology, Okayama University Takayoshi Yokoya Graduate School of Natural Science and Technology, Okayama University La(O,F)BiS2-xSex is a layered material that is considered to be a candidate exotic superconductor as well as a promising thermoelectrical material. We performed soft X-ray photoelectron holography to study the Se incorporation site and the local atomic arrangement of the conducting layer. A comparison of the experimental holograms with the simulated holograms indicates that Se atoms preferentially occupy the S sites in the conducting Bi–S plane of La(O,F)BiS2. A comparison between the state-of-the-art holographic reconstructions of La(O,F)BiSSe and La(O,F)BiS2 suggests that Se substitution suppresses the displacement of S atoms in La(O,F)BiS2. These results provide photoelectron holographic evidence for the Se incorporation site and the Se-induced suppression of in-plane disorder. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 0953-8984 33 3 2020 Soft x-ray irradiation induced metallization of layered TiNCl 035501 EN Noriyuki Kataoka Graduate School of Natural Science and Technology, Okayama University Masashi Tanaka Graduate School of Engineering, Kyushu Institute of Technology Wataru Hosoda Graduate School of Natural Science and Technology, Okayama University Takumi Taniguchi Graduate School of Natural Science and Technology, Okayama University Shin-ichi Fujimori Materials Sciences Research Center, Japan Atomic Energy Agency Takanori Wakita Graduate School of Natural Science and Technology, Okayama University Yuji Muraoka Graduate School of Natural Science and Technology, Okayama University Takayoshi Yokoya Graduate School of Natural Science and Technology, Okayama University We have performed soft x-ray spectroscopy in order to study the photoirradiation time dependence of the valence band structure and chemical states of layered transition metal nitride chloride TiNCl. Under the soft x-ray irradiation, the intensities of the states near the Fermi level (EF) and the Ti3+ component increased, while the Cl 2p intensity decreased. Ti 2p–3d resonance photoemission spectroscopy confirmed a distinctive Fermi edge with Ti 3d character. These results indicate the photo-induced metallization originates from deintercalation due to Cl desorption, and thus provide a new carrier doping method that controls the conducting properties of TiNCl. No potential conflict of interest relevant to this article was reported.