Abstract
Nano-structured functional materials are expected to have superior properties to the coarse-grained, bulk materials. In the present paper, pure palladium is refined to nano-sized state to investigate the hydrogen absorption and desorption behavior. Using the bulk mechanical alloying, the palladium platelets can be successfully refined to nano-sized grains with the order to 10 nm. In comparison of pressure composition isotherms between nano-sized and bulk palladium, the phase boundary of the Pd-H miscibility gap is significantly narrower for nano-Pd. While the hydrogen solubility at α/(α + β) phase boundary is much increased, that at β/(α + β) phase boundary is drastically reduced by nano-structuring. This might be because of the broadening of the site energy distribution, induced by the intrinsic strains constraining the nano-grains. The broadening mechanism of site energy distribution has direct influence on the hydrogen absorption and desorption processes. The Curie temperature for hydrogen adsorption and desorption is drastically reduced by 135 K through the nanostructuring. The above precise discussion helps us to make nanostructured material design in the hydrogen storage alloys and compounds.
Original language | English |
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Pages (from-to) | 960-965 |
Number of pages | 6 |
Journal | Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy |
Volume | 48 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2001 Oct |
Keywords
- Bulk mechanical alloying
- Hydrogen absorption behavior
- Hydrogen desorption behavior
- Hydrogen storage properties
- Intrinsic strains
- Nano-structuring
- Palladium
- Site energy distribution
ASJC Scopus subject areas
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Metals and Alloys
- Materials Chemistry