Time-of-Flight secondary ion mass spectrometry (TOF-SIMS) using the metal-cluster-complex primary ion of Ir4(CO)7+

Yukio Fujiwara*, Naoaki Saito, Hidehiko Nonaka, Atsushi Suzuki, Taisuke Nakanaga, Toshiyuki Fujimoto, Akira Kurokawa, Shingo Ichimura

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


An orthogonal acceleration Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) system has been developed with a metal-cluster-complex ion source. The ion source can produce ion beams of massive molecules called metal-cluster-complexes such as Ir4(CO)12, which has a molecular weight higher than 1000 u. Using the system, TOF-SIMS of a contaminated silicon substrate and a room temperature molten salt (i.e. an ionic liquid) was performed. The ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl)imide, which has a molecular weight of 426 u, consists of a polyatomic cation, [C8H20ON] +, and a polyatomic anion, [C2F6NO 4S2]-. During SIMS analysis, an analytical sample was bombarded with a continuous primary ion beam of either Ir 4(CO)7+ or Ar+ in a beam energy of 10 keV at an incident angle of 45°. It was confirmed that the use of Ir 4(CO)7+ ions enhanced secondary ion intensity compared with that of Ar+ ions. Also, experimental results showed that the bombardment of Ir4(CO)7+ caused less fragmentation. In the case of the ionic liquid, cation-attached ionic-liquid molecules were observed in addition to the cation of the ionic liquid.

Original languageEnglish
Pages (from-to)245-248
Number of pages4
JournalSurface and Interface Analysis
Issue number1-2
Publication statusPublished - 2011 Jan
Externally publishedYes


  • Ir (CO)
  • Ir(CO)
  • SIMS
  • TOF
  • cluster SIMS
  • ion beam
  • ionic liquid
  • metal-cluster-complex
  • orthogonal
  • sputtering

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry


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