1994 Fiscal Year Final Research Report Summary
High-resolution depth profiling of surface hydrogen by a resonant nuclear reaction
| Project/Area Number |
04555001
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied materials
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| Research Institution | University of Tokyo |
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Principal Investigator |
MURATA Yoshitada Institute for Solid State Physics, University of Tokyo, 物性研究所, 教授 (10080467)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUTANI Katsuyuki Institute for Solid State Physics, University of Tokyo, 物性研究所, 助手 (10228900)
FUJIMOTO Koichiro Geographycal Survey of Japan, 地質調査所, 主任研究員
KOBAYASHI Koichi Research Center of Nuclear Science, University of Tokyo, 原子力研究総合センター, 助教授 (70108637)
KOMAKI Kenichiro Graduate School of Arts and Sciences, University of Tokyo, 教養学部, 教授 (40012447)
TERAKURA Kiyoyuki National Institute for Integrated Research Area, 領域研究所, 主席研究官 (40028212)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Hydrogen / Solid surfaces and interfaces / Resonant nuclear reaction / Depth-profiling / Tandem-Accelerator |
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| Research Abstract |
A high-resolution depth-profiling method of hydrogen was developed at the 2C beam line of the new tandem-type Van de Graaph accelerator at the Research Center for Nuclear Science and Technology, University of Tokyo, in aimed at the investigation of hydrogen dynamics at surfaces and interfaces.
The experiment was performed in a ultra-high vacuum chamber equipped with LEED and quadrupole mass spectrometer. The resonance nuclear reaction of ^1H (^<15>N,alphagamma) ^<12>C of which resonance width is 1.8KeV was applied to dydrogen detection. A ^<15>N^<2+> ion at an energy of 6.385 MeV was generated from tandem-type Van de Graaph accelerator with an energy spread of 5 keV.The gamma-ray emitted as a result of the nuclear reaction with hydrogen was detected by a Bi_4Ge_4O_<12> scintillator. The gamma-ray yield as a function of the incident energy shows the depth profile of H of the sample. Since the energy loss of a ^<15>N^<2+> ion at 6.385 MeV in Pb is 0.23 KeV/*, the depth resolution estimated from the resonance, Instrumental and Doppler widths is about 40 *. Samples we used are metal overlayr on Si (lll) 7_x7-H and Si (lll) 1_x1-H,which were prepared by exposing the Si (lll) clean surface to atomic hydrogen untill saturation at sample temperatures of 300 and 700 K,respectively, H-Au (001), and Olivine/Aqueous Solution Interface. Atomic hydrogen was produced by introducing H_2 gas through tungsten tube heated at 1800K.We demonstrated that this method is very powerful for high-resolution depth profiling of hydrogen at a surface and interfaces below the surface.
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