Ray type dependence of radiation induced surface activation phenomenon

Makoto Kariyazaki, Hiroaki Abe, Akio Sayano, Fumihisa Kano, Yoshio Katano, Takashi Onitsuka, Naoto Sekimura

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The phenomenon named Radiation Induced Surface Activation (RISA) was discovered recently. It is a phenomenon involving the activation of surfaces of metallic oxides attributable for strong affinity for water. In this work, we examined wettability increase under irradiations with γ-ray and UV, as well as its degradation under non-irradiation condition by measuring the changes of water contact angle on oxide layers formed onto Zircaloy-4 plates. The water contact angle for the sample surface decreased gradually under irradiation, and increased gradually by darkroom storage after irradiation. The theoretical formula, which describes the development of the hydrophilic surface under irradiation and its stability, was fitted to the experimental results, It caused us to propose the existence of two kinds of hydrophilic factors in terms of stability, whose formation probabilities depend on the type of irradiation.

Original languageEnglish
Pages (from-to)423-426
Number of pages4
JournalNippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
Issue number4
Publication statusPublished - 2007 Apr


  • Contact angle
  • Hydrophilicity
  • Ultra violet (UV)
  • Wettability
  • Zircaloy
  • Zirconium oxide
  • γ-ray

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry


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