MAGNETIZATION BEHAVIOR OF HYDROGEN STORAGE MMNI(5) INTERMETALLICS WITH AL, MN AND SN SUBSTITUTIONS

The magnetization behavior of annealed hydrogen storage MmNi(5-x)Al(x) (x = 0.4, 0.8), MmNi(5-x)Mn(x) (x = 0.4, 0.8) and MmNi(4.6)Sn(0.4) in termetallics has been studied. Al, Mn and Sn substitutions systematica lly decreased the saturation magnetization due to the filling of the 3 d band of nickel by the electrons from substituted elements. The decre ase in saturation magnetization is related to the lowering of hydride formation pressure of these intermetallics by the substituted elements . Al substitutions decreased whereas Mn substitutions increased the hy drogen storage capacity. The lowering of plateau pressure and increase or decrease in hydrogen storage capacity when Ni is partially substit uted with Al, Mn and Sn is correlated to the changes in relative magne tic moment. (C) 1997 International Association for Hydrogen Energy.