On the synthesis, characterization and hydrogenation behaviour of Fe1 $minus; 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 has been synthesised through RF melting. The XRD and TEM characterization of Fe0.8Ti1.3Ni0.2 revealed the occurrence of curious structural phases; namely, a superlattice with “a” periodicity of 5.93 A (which is double that of the 2.98 A FeTi1.3 phase) and a modulated phase having a modulation period of 4 times along [110] as compared to d110 of the superlattice phase. The Fe0.8Ti1.3Ni0.2 phase has been found to have faster hydrogen desorption kinetics (30–40 cc/min) which 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 material is biphasic in nature and embodies built-in interfaces and has faster crack propagation on hydrogenation.