Akira Chikamatsu, Ayuka Nakano, Miku Hagiwara, Dai Kutsuzawa, Erika Fukushi, Hiroyuki Oguchi, Fumihiko Uesugi, Tsukasa Katayama, and Yasushi Hirose, “Crystal structure and fluoride-ion conductivity of strontium cerium fluoride epitaxial films prepared by topochemical fluorination”, Chem. Commun. 61, 12317-12320 (2025). (DOI: 10.1039/D5CC00985E.)
Akiko Kamigaito, Mizuho Sano, Kei Shigematsu, Satoshi Demura, Hiroshi Kumigashira, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Ferroelectricity and magnetic order at room temperature and electronic states of bismuth iron oxyfluoride thin films”, J. Appl. Phys. 137, 214101-1-8 (2025). (DOI: 10.1063/5.0263144.)
Tsukasa Katayama, Akira Chikamatsu, and Motoaki Hirayama, “Antiferroelectric Behavior in Mixed-Anion Bi2TiO4F2 Induced by Rotation of TiO3F3 Octahedra”, Adv. Funct. Mater. 2500489 (2025). (DOI: 10.1002/adfm.202500489.)
Mizuho Sano, Akiko Kamigaito, Yusuke Wakayama, Kei Shigematsu, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Topochemical Fluorination of Epitaxial Thin Films of Barium-Doped Bismuth Iron Oxyfluoride”, Cryst. Growth Des. 24, 9344-9349 (2024). (DOI: 10.1021/acs.cgd.4c00552.)
Akiko Kamigaito, Mizuho Sano, Kei Shigematsu, Hiroshi Kumigashira, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu*, “Electronic states of perovskite-type bismuth iron oxyfluoride thin films”, Photon Factory Activity Report 2023 41, 98 (2024).
Tsukasa Katayama, Kento Magara, Shiro Sakai, Yijie Zeng, Akira Chikamatsu, and Tetsuya Hasegawa, “Cation-placement control in double-perovskite GdBaCo2O6 and its impact on magnetism via spin-state modification”, J. Mater. Chem. C 12, 10428-10436 (2024). (DOI: 10.1039/D4TC01498G)
Lizhikun Gong, Ko Marunouchi, Akira Chikamatsu, Hiromichi Ohta, and Tsukasa Katayama, “Large tensile-strained BaTiO3 films grown on a lattice-mismatched La-doped BaSnO3 bottom electrode”, CrystEngComm 26, 2765-2769 (2024). (DOI: 1039/D4CE00197D)
Takashi Yanase, Miu Ebashi, Kotaro Takamure, Wataru Ise, Hiroki Waizumi, Akira Chikamatsu, Yasushi Hirose, and Toshihiro Shimada, “Unidirectional growth of epitaxial tantalum disulfide triangle crystals grown on sapphire by chemical vapour deposition with a separate-flow system”, CrystEngComm 26, 341-348 (2024). (DOI: 10.1039/D3CE00906H)
Tsukasa Katayama, Kento Magara, Akira Chikamatsu, and Tetsuya Hasegawa, “Anisotropic Proton Conduction in Double-Perovskite GdBaCo2O5”, Appl. Phys. Lett. 123, 012902 (2023). (DOI: 10.1063/5.0153239)
Tsukasa Katayama, Shishin Mo, Akira Chikamatsu, and Tetsuya Hasegawa, “Solid Phase Epitaxy of Perpendicular Magnetic BaFe12O19 Flexible Sheets on a Mica Substrate”, Jpn. J. Appl. Phys. 62, 065505 (2023). (DOI: 10.35848/1347-4065/acda01)
Hong Yan, Kotaro Fujii, Houria Kabbour, Akira Chikamatsu, Yu Meng, Yoshitaka Matsushita, Masatomo Yashima, Kazunari Yamaura, and Yoshihiro Tsujimoto, “La4Ga2S8O3: A Rare-Earth Gallium Oxysulfide with Disulfide Ions”, Inorg. Chem. 62, 10481-10489 (2023). (DOI: 10.1021/acs.inorgchem.3c01524)
Shishin Mo, Tsukasa Katayama, Akira Chikamatsu, and Tetsuya Hasegawa “Grain Engineered Polar-Axis-Oriented Epitaxial Mn2Mo3O8 Films with Enhanced Magnetic Transition Temperature”, J. Mater. Chem. C 11, 7427-7432 (2023). (DOI: 10.1039/D3TC00730H)
Tsukasa Katayama, Shishin Mo, Akira Chikamatsu, Yuji Kurauchi, Hiroshi Kumigashira, and Tetsuya Hasegawa, “Half-Metallicity and Magnetic Anisotropy in Double-Perovskite GdBaCo2O6 Films Prepared via Topotactic Oxidation”, Chem. Mater. 35, 1295-1300 (2023). (DOI: 10.1021/acs.chemmater.2c03335)
Takahiro Maruyama, Yasushi Hirose, Tsukasa Katayama, Yuki Sugisawa, Daiichiro Sekiba, Tetsuya Hasegawa, and Akira Chikamatsu*, “Negative Magnetoresistance in Different Nitrogen Content EuNbO3-xNx Single-Crystalline Thin Films”, J. Mater. Chem. C 10, 14661-14667 (2022). (DOI: 10.1039/D2TC03328C)
Jun Kasahara, Tsukasa Katayama, Akira Chikamatsu, Yosuke Hamasaki, and Tetsuya Hasegawa, “Epitaxial Growth of Hexagonal GdFeO3 Thin Films with Magnetic Order by Pulsed Laser Deposition”, Thin Solid Films 757, 139409 (2022). (DOI: 10.1016/j.tsf.2022.139409)
Tsukasa Katayama, Akira Chikamatsu, and Tetsuya Hasegawa, “Ionic Order and Magnetic Properties of Double-Perovskite GdBaCo2O5 Films on SrTiO3 Substrates”, J. Ceram. Soc. Japan 130, 429-431 (2022). (DOI: 10.2109/jcersj2.21174)
Shota Fukuma, Akira Chikamatsu*, Tsukasa Katayama, Takahiro Maruyama, Keiichi Yanagisawa, Koji Kimoto, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Yasushi Hirose, and Tetsuya Hasegawa, “Crystal Structure and Electronic Property Modification of Ca2RuO4 Thin Films via Fluorine Doping”, Phys. Rev. Mater. 6, 035002 (2022). (DOI: 10.1103/PhysRevMaterials.6.035002)
Yujun Zhang, Tsukasa Katayama, Akira Chikamatsu, Christian Schüßler-Langeheine, Niko Pontius, Yasuyuki Hirata, Kou Takubo, Kohei Yamagami, Keisuke Ikeda, Kohei Yamamoto, Tetsuya Hasegawa, and Hiroki Wadati, “Photo-Induced Antiferromagnetic-Ferromagnetic and Spin-State Transition in a Double-Perovskite Cobalt Oxide Thin Film”, Commun. Phys. 5, 50 (2022). (DOI: 10.1038/s42005-022-00823-4)
Takuma Nishimura, Tsukasa Katayama, Shishin Mo, Akira Chikamatsu, and Tetsuya Hasegawa, “Improvement of Electric Insulation in Dielectric Layered Perovskite Nickelate Films via Fluorination”, J. Mater. Chem. C 10, 1711-1717 (2022). (DOI: 10.1039/D1TC04755H)
Akira Chikamatsu*, Shota Fukuma, Tsukasa Katayama, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, and Tetsuya Hasegawa, “Ru oxidation states in fluorinated Ca2RuO4 thin films revealed by X-ray photoemission spectroscopy”, Photon Factory Activity Report 2021 39, 156 (2022).
Yannan Wang, Yasushi Hirose, Takuto Wakasugi, Yuji Masubuchi, Masato Tsuchii, Yuki Sugisawa, Daiichiro Sekiba, Akira Chikamatsu, and Tetsuya Hasegawa, “Heteroepitaxial Growth of a Ta3N5 Thin Film with Clear Anisotropic Optical Properties”, J. Phys. Chem. Lett. 12, 12323-12328 (2021). (DOI: 10.1021/acs.jpclett.1c03673)
Presentation (Since October 2021)
Akiko Kamigaito, Kei Shigematsu, Masaki Kobayashi, Hiroshi Kumigashira, Kenta Amemiya, and Akira Chikamatsu, “Analysis of Fe Electronic States in Bi8Ba0.2FeO2.9 and Bi0.8Ba0.2FeO2.8F0.2 Thin Films Using X-ray Spectroscopy”, Annual Meeting of the Japan Society of Vacuum and Surface Science 2025, TSUKUBA International Congress Center, (Tsukuba, Japan), October 2025, 1F08-15. (Oral)
Ayuka Nakano, Miku Hagiwara, Fumihiko Uesugi, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Topochemical fluorination of perovskite SrCeO3 epitaxial thin films”, The Japan Society of Vacuum and Surface Science Kanto Chapter 10th Anniversary Symposium, TOKI MESSE Niigata Convention Center, (Niigata, Japan), April 2025, P14. (Poster)
Miku Hagiwara, Ayuka Nakano, Dai Kutsuzawa, Erika Fukushi, Hiroyuki Oguchi, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Fluoride-ion conductivity of strontium cerium fluoride epitaxial thin films”, The Japan Society of Vacuum and Surface Science Kanto Chapter 10th Anniversary Symposium, TOKI MESSE Niigata Convention Center, (Niigata, Japan), April 2025, P15. (Poster)
Akiko Kamigaito, Mizuho Sano, Kei Shigematsu, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Structural changes in bismuth iron oxide epitaxial thin films via topochemical fluorination”, The Japan Society of Vacuum and Surface Science Kanto Chapter 10th Anniversary Symposium, TOKI MESSE Niigata Convention Center, (Niigata, Japan), April 2025, P16. (Poster)
Reina Tsuiji, Miori Kishi, Akiko Kamigaito, Yasushi Hirose, and Akira Chikamatsu, “Topochemical fluorination of yttrium-barium ferrite epitaxial thin films”, The Japan Society of Vacuum and Surface Science Kanto Chapter 10th Anniversary Symposium, TOKI MESSE Niigata Convention Center, (Niigata, Japan), April 2025, P17. (Poster)
Akira Chikamatsu, “Topochemical fluorination of transition metal oxide thin films”, Mini Workshop on Functional Materials Science, Hokkaido Univ. (Sapporo, Janan), December 2023. (Invited, Oral)
Akiko Kamigaito, Mizuho Sano, Kei Shigematsu, Satoshi Demura, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Ferroelectric and magnetic properties of a perovskite-type bismuth iron oxyfluoride thin film”, The 14th APCTP Workshop on Multiferroics, Univ. of Tokyo (Tokyo, Japan), October 2023, PS-04. (Poster)
Mizuho Sano, Akiko Kamigaito, Tsukasa Katayama, Yasushi Hirose, and Akira Chikamatsu, “Topochemical fluorination of bismuth iron oxide epitaxial thin films”, The 14th APCTP Workshop on Multiferroics, Univ. of Tokyo (Tokyo, Japan), October 2023, PS-05. (Poster)
Akira Chikamatsu, Shota Fukuma, Tsukasa Katayama, Takahiro Maruyama, Keiichi Yanagisawa, Koji Kimoto, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Yasushi Hirose, and Tetsuya Hasegawa, “Crystal structure and electronic property modification of layered calcium ruthenium oxyfluoride thin films”, The 22nd International Vacuum Congress IVC-22, Sapporo Convention Center (Sapporo, Japan), September 2022, Mon-G2-6. (Oral)
Tsukasa Katayama, Akira Chikamatsu, and Tetsuya Hasegawa, “Ionic-order engineering in double-perovskite cobaltite”, The 22nd International Vacuum Congress IVC-22, Sapporo Convention Center (Sapporo, Japan), September 2022, Tue-P01D-9. (Poster)
近松 彰, 長谷川 哲也, “Layered ruthenium and iridium oxyfluoride thin films fabricated via topochemical fluorination”, 第46回日本磁気学会学術講演会, 信州大学(長野県長野市), 2022年9月, D-I6-009.(招待講演, 口頭)
Akira Chikamatsu, “Topochemical synthesis of mixed-anion oxide epitaxial thin films”, 2022 MRS Spring Meeting, Online, May 2022, SF11.08.01. (Invited, Oral)
Akira Chikamatsu and Tetsuya Hasegawa, “Modulating physical properties of strongly correlated oxide thin films by anion doping”, The Materials Research Meeting 2021, PACIFICO YOKOHAMA (Yokohama, Japan), December 2021, D2-O1-02. (Invited, Oral)
Shishin Mo, Tsukasa Katayama, Akira Chikamatsu, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Tetsuya Hasegawa, “Epitaxial-strain-induced Spontaneous Magnetization in Polar Mn2Mo3O8”, The Materials Research Meeting 2021, PACIFICO YOKOHAMA (Yokohama, Japan), December 2021, D2-O1-06. (Oral)
Awards (Since October 2021)
Akiko Kamigaito, Outstanding Student Poster Award: “Structural changes in bismuth iron oxide epitaxial thin films via topochemical fluorination”, The Japan Society of Vacuum and Surface Science Kanto Chapter 10th Anniversary Symposium, April 2025.