1992 Fiscal Year Final Research Report Summary
Atomic and electronic structures of hydrogenated rare-earth glasses
| Project/Area Number |
02452233
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
TANAKA Kazuhide Nagoya Institute of Technology, Prof, 工学部, 教授 (00024232)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Masaaki Nagoya Institute of Technology,Assis, 工学部, 助手 (30024342)
YOSHINARI Osamu Nagoya Institute of Technology,Assoc, 工学部, 助教授 (10134040)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Glassy alloys / Rare-earth metal / Transition metal / Hydrogen / Atomic structure / Electronic structure / Hydrogen-storage alloys / Surface properties |
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| Research Abstract |
It is well known that rare-earth (RE) -transition metal (TM)- simple metal (SM) systems readily form glassy alloys over wide composition ranges and are very reactive to hydrogen. In this research, atomic and electronic structures and surface states of La-Ni-Mg(Al) and Nd-Fe-B alloy glasses and their hydrides have been studied by means of X-ray diffraction, X-ray photoemission spectroscopy and thermal desorption spectrometry. In all these systems the glass structures consist of random packing of the metal atoms, where however RE-TM interaction is strengthened. Hydrogenation alters the random structures by forming strong RE-H chemical bonds, which break the RE-TM bonds and cause micro-clustering of metal atoms. This effect was observed by radial distribution analysis of atomic structure and photoemission core-level and valence-band spectra consistently.
Hydrogen can be stored in these glasses by H/M=1.0-1.7 depending on the compositions. Their hydrogen absorption-desorption properties have been studied in detail. Specifically, La_5Ni_<40>Mg_<55> alloy glass is found to be profitable for use as a hydrogen storage material.
These studies have been published in regular papers and are going to be presented at international symposiums.
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