Anodic formation and properties of nanoscale oxide layers on silver–zinc alloys with different concentrations of non-equilibrium vacancies

Anodic oxidation of silver – zinc alloys with a concentration of zinc of up to 30 at.% (alpha phase) in a deaerated aqueous solution of 0.1 M KOH was studied by voltammetry and chronoamperometry with synchronous registration of the photocurrent. A preliminary modification of the alloy surface due to the selective zinc dissolution, with monitoring of the potential and charge, was carried out in a deaerated aqueous solution of 0.01 M HNO 3 + 0.09 M KNO 3 . As a result of the modification, the surface layer of the alloy was enriched with an electropositive component and vacancies, whose concentration exceeded the equilibrium concentration. The anodically formed Ag(I) oxide was characterized by an n -type conductivity and the predominance of donor defects in the crystal lattice. Their concentration increased and the width of the space charge region of the semiconductor oxide decreased with an increase in the concentration of non-equilibrium vacancies in the surface layer of the alloy.