Room-Temperature Preparation of Ta Ions-Containing Ionic Liquid and its Vapor Deposition toward Ta-Oxide Film Coating

Nana Hozuki, Kenichi Kaminaga, Shingo Maruyama, Daisuke Shiga, Hiroshi Kumigashira, Hidetaka Takato, Michio Kondo, Yuji Matsumoto

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Ta ions-containing solutions, which are brown in color with no precipitation, were successfully prepared through an electroelution process with ionic liquid (IL). An as-delivered Ta metal plate covered with a passivation oxide film could be easily eluted even at room temperature by simply applying an anodic potential of, e.g. +2.2 V vs Ag in [Bmim][PF6] IL. According to the quantity of electric charge required for oxidation of Ta, most Ta ions in the IL were suggested to be in an oxidation state of +5, which was also confirmed by X-ray photoemission spectroscopy (XPS). Ta ions in IL were found to thermally evaporate together with IL molecules by heating in a vacuum, forming a deposit of the Ta ions-containing IL on a substrate. The Ta concentrations in the deposits were reduced uniquely by about one order of magnitude from those in the original bulk source through the evaporation process under the present conditions. Furthermore, a possibility of the formation of thin film-like Ta oxide from such a Ta ions-containing IL deposit and its bulk droplet prepared on substrates by annealing in air at 1000 C will be discussed.

Original languageEnglish
Article number013504
JournalJournal of the Electrochemical Society
Issue number1
Publication statusPublished - 2022 Jan

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry


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