Structural and hydrogen solubility studies on ZrMnFe<inf>1-x</inf>Co<inf>x</inf> (x = 0.2, 0.3 and 0.5) alloys

The hydrogen solubility properties in ZrMnFe1-xCox (x = 0.2, 0.3 and 0.5) alloys have been studied in the ranges 10≤P(mbar)≤1000 and 30≤T(C)≤100 using low pressure unit based on the pressure reduction method. The powder X-ray diffractograms show that the lattice constants and the unit cell volume of C 14 based ZrMnFe1-xCox (x = 0.2. 0.3 and 0.5) alloys decrease with increase of Co content. Comparing with the hydrogen solubility properties in ZrMnFe, it has been found that the substitution of Co at Fe site in ZrMnFe decreases the hydrogen solubility (r = nH/nf.u.), except in ZrMnFe0.5Co0.5. This suggests that in ZrMnFe0.5Co0.5, the electronic effects are dominant over the size effects in determining the hydrogen solubility properties due to the charge transfer effects between Fe/Co ligand and hydrogen atom.