[14p-B6-1~12] 7.5 Ion beams

[14p-B6-8] Atom probe analysis of glycine molecules formed on tungsten tip

〇Yuki Haneji¹, Noriaki Nyuba¹, Chikasa Nishimura¹, Tasuku Sone¹, Hiroshi Tsuji¹, Yasuhito Gotoh¹ (1.Kyoto Univ.)

Keywords:atom probe analysis, time-of-flight mass analysis, glycine

We have previously shown a newly developed time-of-flight mass spectrometer with a capability of identification of lighter atom ions. In this study, time-of-flight measurement with the spectrometer was performed in ion beam extracted from glycine. The simplest structural amino acid, glycine, was formed on a sharp tungsten tip by vacuum deposition. The obtained mass spectra exhibit the dependence of produced ion species depending on field strength. In a condition of limited evaporation yields by dc voltage application to the specimen, singly charged monomer were measured. Given higher tip voltage, doubly charged monomer and a specific fragment pair upon C-C bond dissociation were predominantly detected. Our results suggest that tip voltage level control determines the produced ion species during atom probe analysis, preventing overlaps in mass spectrum and providing possibility of further accurate identification of ions.