Hydrogen sorption properties of the LaNi5-xGax alloys
A series of ternary alloys based on LaNi5 was prepared by substituting up to 50 at.% of gallium for nickel. X-ray powder diffraction revealed that the hexagonal structure of LaNi5 (CaCu5 type; space group P6/mmm) is preserved in all ternary alloys and that the unit cell parameters increase with the...
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| Published in | Journal of alloys and compounds Vol. 359; no. 1-2; pp. 180 - 185 |
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| Main Authors | , |
| Format | Journal Article |
| Language | English |
| Published |
22.09.2003
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| Online Access | Get full text |
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| Summary: | A series of ternary alloys based on LaNi5 was prepared by substituting up to 50 at.% of gallium for nickel. X-ray powder diffraction revealed that the hexagonal structure of LaNi5 (CaCu5 type; space group P6/mmm) is preserved in all ternary alloys and that the unit cell parameters increase with the gallium concentration. The alloys were exposed to hydrogen gas and the pressure-composition desorption isotherms for the alloy-hydrogen systems were determined. It was found that substitution of gallium for nickel decreases the hydrogen capacity and the hydrogen equilibrium pressure of the corresponding alloy-hydrogen system. The thermodynamic parameters of hydride formation, i.e. the entropy change, the enthalpy and the Gibbs free energy of formation were derived from desorption isotherms for those alloy-hydrogen systems that exhibit plateau pressures. |
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| Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/S0925-8388(03)00209-3 |