ALUMINUM UNDERPOTENTIAL DEPOSITION FROM ALCL3+NACL MELTS ON GOLD ELECTRODES

Aluminium was incorporated into gold electrodes by underpotential depo sition from an equimolar AlCl3+NaCl melt at 200 degrees C, 250 degrees C, and 300 degrees C. The process was studied by linear sweep voltamm etry together with potentiostatic deposition/galvanostatic stripping. The deposits were characterised by electron microprobe analysis and gl ancing incidence X-ray diffraction. The electrochemical measurements s howed clear evidence of intermetallic compound formation, and this was confirmed by the analysis, which showed several layers of successive bulk intermetallic compounds. The integral Gibbs energy of formation o f the compounds is calculated and the kinetics of growth are described . (C) 1997 Elsevier Science S.A.