Plasma and Fusion Research

Volume 13, 3406065 (2018)

Regular Articles

Nanostructure Growth on Rhodium/Ruthenium by the Exposure to He Plasma
Tomohiro NOJIMA, Shin KAJITA1), Naoaki YOSHIDA2), Shota KAWAGUCHI, Noriyasu OHNO, Hirohiko TANAKA, Masayuki TOKITANI3), Daisuke NAGATA3), Tsuyoshi AKIYAMA3) and Takashi YAGI4)
Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
1)
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
2)
Research Institute for Applied Mechanics, Kyushu University, Fukuoka 819-0395, Japan
3)
National Institute for Fusion Science, Toki 509-5292, Japan
4)
National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8563, Japan
(Received 28 December 2017 / Accepted 18 April 2018 / Published 12 June 2018)

Abstract

Rhodium and ruthenium thin film coatings were conducted on tungsten samples by using a magnetron sputtering device; then, we irradiated He plasma to the samples in the linear plasma device NAGDIS-II (Nagoya Divertor Simulator). Fuzzy nanostructures were formed on rhodium and ruthenium samples when the surface temperatures were ∼950 and ∼1200 K, respectively. When the surface temperature was high, i.e., >1200 K, it was found that tungsten atoms diffused across the rhodium film and reached the film surface, and tungsten-fuzz was formed over the rhodium layer. From TEM analysis of ruthenium fibers, it was identified that there were thin parts in the fibers, and some fibers had no He bubbles. It was likely that fiber growth mechanism on ruthenium was different from the other metals.

Keywords

rhodium, ruthenium, fuzz, percolation, morphology change

DOI: 10.1585/pfr.13.3406065

Full Text

PDF format (3.4Mbytes) PDF Download

References

  • [1] S. Takamura et al., Plasma Fusion Res. 1, 051 (2006).
  • [2] M. de Respinis et al., ACS Appl. Mater. Interface 5, 7621 (2013).
  • [3] S. I. Krasheninnikov, Phys. Scr. T145, 014040 (2011).
  • [4] Yu.V. Martynenko and M.Yu. Nagel, Plasma Phys. Rep. 38, 12, 996 (2012).
  • [5] S. Kajita et al., New J. Phys. 17, 043038 (2015).
  • [6] K.B. Woller, D.G. Whyte and G.M. Wright, Nucl. Fusion 57, 066005 (2017).
  • [7] S. Kajita et al., Sci. Rep. (to be published in).
  • [8] R.D. Smirnov and S.I. Krasheninnikov, Nucl. Fusion 53, 082002 (2013).
  • [9] S. Kajita et al., Sci. Rep. 6, 30380 (2016).
  • [10] S. Takamura and T. Uesugi, Appl. Surf. Sci. 356, 888 (2015).
  • [11] S. Kajita et al., Nucl. Fusion 49, 095005 (2009).
  • [12] J.K. Tripathi et al., Appl. Surf. Sci. 353, 1070 (2015).
  • [13] J. Merker et al., Platinum Metals Rev. 45, (2), 74 (2001).
  • [14] E.P. Papadakis et al., J Appl. Phys. 45, 6 (1974).
  • [15] N. Ohno et al., Nucl. Fusion 41, 8 (2001).
  • [16] S. Kajita et al., J. Nucl. Mater. 418, 152 (2011).
  • [17] S. Kajita et al., Surf. Coats. Tech. 340, 86 (2018).
  • [18] K. Wang et al., Sci. Rep. 7, 42315 (2017).
  • [19] M. Yajima et al., J. Nucl. Mater. 449, 9 (2014).
  • [20] A. Litnovsky et al., Fusion Eng. Des. 123, 674 (2017).
  • [21] T.B. Massalski et al., Binary Alloy Phase Diagrams 5 (ASM international 1990).