THE ELECTROCHEMICAL BEHAVIOUR OF La~(3+) OVER Ni AND Mo, IN MOLTEN SALTS CHLORIDE

摘要

The intermetallic compound, LaNi_5, has high capacity of hydrogen absorption and could be obtained by electrolysis in molten salts with advantages, in front of the traditional methods of arc melting or sputtering, how higher mechanical strenght and better hydrogen absorption properties. The electrochemical behaviour of La~(3+), with the purpose of the LaNi_5 formation, was studied by the reduction of the lanthanide ion, in the anhydrous LaCl_3+NaCl-KCl (1:1), over Ni and Mo electrodes. The cyclic voltammetry and chronopotentiometry was employed, between 700°C and 800°C. Lanthanum electrodeposition over the substrates occured in one step of charge transfer, of three electrons. The results indicated the formation of several fases of intermetallic compounds of the La-Ni system.