Gravimetry, ac impedance, X-ray photoelectron spectroscopy, and anodic polarization curves are used to demonstrate that the Al-Zn(45 wt %) alloy has a lower corrosion resistance in a 0.5 M NaVO3 solution at 298 K than the same alloy microdoped with rare earths (0.1 wt %). The minimum electrode capacitance at the metal-solution interface is displayed by the Al-Zn (45 wt %) alloy, and the maximum, by the Al-Zn (45 wt %)Sc (0.1 wt %) alloy; the latter is also characterized by a minimum current density of anodic passivation. © 1998 MAHK Hayka/Interperiodica Publishing.