Abstract
Hydrogen absorbing properties of ScM2 (M = Fe, Co and Ni) Laves phase alloys were studied by pressure-composition (PC) isotherm measurements at the temperature range from 293 K to 353 K. Crystal structural change of these alloys during hydrogenation was also studied by in situ X-ray powder diffraction measurements under hydrogen pressure up to 4 MPa. Clear plateaus were observed in all the absorption and desorption isotherms. The enthalpy of formation of ScM2Hx (M = Fe, Co and Ni) was estimated from the equilibrium plateau pressure observed in the PC isotherm to be -28(1), -30(1) and -16(2), respectively, in units of kJ per mol H2. In situ X-ray diffraction measurements revealed that the hydrogenation did not produce any change in metal substructure or any indication of amorphization in the ScM2-H2 systems (M = Fe, Co and Ni). The cell volume, however, increased by 23.1% (Fe), 21.0% (Co) and 14.5% (Ni) upon hydrogenation.
Original language | English |
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Pages (from-to) | 75-80 |
Number of pages | 6 |
Journal | Journal of Alloys and Compounds |
Volume | 226 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - Aug 1 1995 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry