Particulate Generation on Surface of Iron Selenide Films by Air Exposure


Nanometer-sized particular structures are generated on the surfaces of FeSe epitaxial films directly after exposure to air; this phenomenon was studied in the current work because these structures are an obstacle to field-induced superconductivity in electric double-layer transistors using FeSe channel layers. Chemical analyses using field-effect scanning Auger electron spectroscopy revealed no clear difference in the chemical composition between the particular structures and the other flat surface region. This observation limits the possible origins of the particulate formation to light elements in air such as O, C, H, and N.

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This work was supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) through the Element Strategy Initiative to Form Core Research Center. H. Hi. was also supported by the Japan Society for the Promotion of Science (JSPS) through Grant-in-Aid for Scientific Researches (A) and (B) (Grant Nos. 17H01318 and 18H01700), and Support for Tokyotech Advanced Research (STAR).

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Correspondence to Hidenori Hiramatsu.

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Hiramatsu, H., Hanzawa, K., Kamiya, T. et al. Particulate Generation on Surface of Iron Selenide Films by Air Exposure. J Supercond Nov Magn 32, 3047–3055 (2019).

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  • Iron-based superconductors
  • Chalcogenides
  • FeSe
  • Electric double-layer transistor
  • Degradation