ON THE SYNTHESIS, CHARACTERIZATION AND HYDROGENATION BEHAVIOR OF FE1-XTI1+YNIX(X=0.2,Y=0.3) HYDROGEN STORAGE MATERIAL

The hydrogen absorption characteristics of TiFe partially substituted with small amount of Ni for Fe and corresponding to Fe0.8Ti1.3Ni0.2 ha s been synthesised through RF melting. The XRD and TEM characterizatio n of Fe0.8Ti1.3Ni0.2 revealed the occurrence of curious structural pha ses; namely, a superlattice with ''a'' periodicity of 5.93 Angstrom (w hich is double that of the 2.98 Angstrom FeTi1.3 phase) and a modulate d phase having a modulation period of 4 times along [110] as compared to d(110) of the superlattice phase. The Fe0.8Ti1.3Ni0.2 phase has bee n found to have faster hydrogen desorption kinetics (30-40 cc/min) whi ch is about 2-3 times higher than that of the parent phase FeTi1.3. It has been suggested that the faster desorption kinetics are due to the Ni substitution leading to the material Fe0.8Ti1.3Ni0.2. This materia l is biphasic in nature and embodies built-in interfaces and has faste r crack propagation on hydrogenation. (C) 1997 International Associati on for Hydrogen Energy.