  The present research work is focused on the effect of activation procedure on
the hydrogen absorption-desorption properties of new rare earth transition
metal compound based on Sm(Co0.6Fe0.2Zr0.16B0.04)7.5 composition. Crystal
structure and composition is always connected to the maximum capacity of the
intermetallic hydrides. For composite materials the thermodynamic properties of
hydrogenation & dehydrogenation procedure are mostly explained through
microstructure-microchemistry characteristics. Efficient hydrogen storage is
direct connected to the desorbed hydrogen amount. The as hydrogenated material
Sm(Co0.6Fe0.2Zr0.16B0.04)7.5 seems to have in the desorption a pressure plateau
below the atmospheric pressure at room temperature while the absorbed hydrogen
almost remains in the material having capacity of ~0.8 wt. % at 0.1 MPa - 30
oC. After the proper activation procedure, the hydrogenated material desorbs
very high amount of hydrogen ~1.9 wt. % at 0.1 MPa - 100 oC. Subsequently, the
treatment of the composite materials before hydrogenation & dehydrogenation
procedures could play a crucial role on the efficiency.
