La corrosion des métaux et alliages

The Reaction of Germanium with Nitric Acid Solutions

“…An increase in the concentration of undissociated HNO~ would lead to increased rate according to Eq. [2]. Lack of suitable concentration and dissociation data under the present experimental conditions prevents a quantitative treatment of this effect.…”

“…13. [2]. 2 shows that, in general, the dissolution rate is not significantly affected by the presence of HF at HNO3 concentrations below 6N without stirring and 8N with stirring.…”

“…The rate of formation of GeO, increases as the rate of the cathodic reaction increases according to [2]. The rate of formation of GeO, increases as the rate of the cathodic reaction increases according to [2].…”

“…Where there is little solvent action, thin nonporous films, whose thickness is proportional to the applied voltage, are formed (2). When there is appreciable solvent action, thick porous films, whose thickness increases with the time anodized, are formed (3).…”

“…The formation of a layer of GeO2 at high HNO.~ concentrations is explained as follows. The rate of formation of GeO, increases as the rate of the cathodic reaction increases according to [2]. At the same time, however, the solubility and/or the dissolution rate of the oxide decreases.…”