2004 Fiscal Year Final Research Report Summary
Chemical States of Fe atoms Implanted into Solid Oxygen
| Project/Area Number |
15550058
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic chemistry
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| Research Institution | RIKEN |
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Principal Investigator |
KOBAYASHI Yoshio RIKEN, Asahi Applied Nuclear Physics Laboratory, Senior Scientist, 旭応用原子核物理研究室, 先任研究員 (30221245)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Wataru Osaka University, Department of Chemistry, Assistant, 理学部, 助手 (90333319)
UENO Hideki RIKEN, Asahi Applied Nuclear Physics Laboratory, Senior Scientist, 旭応用原子核物理研究室, 先任研究員 (50281118)
YAMADA Yasuhiro Tokyo University of Science, Department of Chemistry, Professor, 理学部, 教授 (20251407)
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| Project Period (FY) |
2003 – 2004
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| Keywords | in-beam Mossbauer spectroscopy / solid oxygen / iron oxides / the ab-initio molecular orbital calculations / matrix isolation / ^<57>Mn / chemical donding / ion implantation |
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| Research Abstract |
We have performed an in-beam Mossbauer spectroscopic experiment using a short-lived ^<57>Mn(T_<1/2>=1.5 min) beam, in order to study the production of the novel chemical species of ^<57>Fe atoms arising from ^<57>Mn implanted into solid oxygen. It is expected that the high electron affinity of oxygen favors the production of high valence states of Fe.
^<57>Mn particles were produced as a secondary RI beam following a nuclear projectile-fragmentation reaction of ^<58>Fe beams (E=63 MeV/nucleon) with Be production target, and separated by the in-flight isotope separator using RIPS(Riken Projectile-fragment Separator) in RIKEN Accelerator Research Facility. Subsequently, the ^<57>Mn was implanted into a solid O_2 sample after passing through an Al plate with an appropriate thickness to suppress the beam energy down to about 20 MeV/nucleon. The in-beam Mossbauer spectra were measured at 18, 32 and 40 K during the implantation of ^<57>Mn. The obtained spectrum at 18 K could be analyzed by 4 sets of Lorentzian doublet. From the basis of Mossbauer parameters of the isomer shifts and the quadrupole splittings and the ab-initio molecular orbital calculations, these 4 components were assigned to be Fe(O_2), FeO, and (O_2)Fe(O_2), and a chemical species in a higher oxidation state of Fe atoms. We discussed the reaction products between ^<57>Fe atoms arising from ^<57>Mn and a solid O_2 matrix, compared with the products of laser-ablated Fe atoms with O_2 gas isolated in the Ar matrix at low temperatures.
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