Etude en microscopie electronique de la morphologie des depôts electrolytiques de zinc

Zinc electrodeposits prepared in alkaline or acidic media have three successive aspects for increasing currents: spongy, compact and dendritic. This sequence is in good agreement with some recent electrochemical kinetic studies which predict, in peculiar conditions, a current distribution on the surface. Using transmission and scanning electron microscopy, morphological and structural characteristics of the electrodeposits have been investigated. Spongy deposits are made of whiskers or microdendrites which grow from a compact substrate. Dendrites obtained at high current density are two-dimensional or three-dimensional. They are initiated by a nucleation process.