A study of nickel passivity by nuclear microanalysis of O16 and O18 isotopes

✍ Scribed by J. Siejka; C. Cherki; J. Yahalom

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 766 KB
• Volume: 17
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(72)85017-5

✦ Synopsis

The passivity of nickel in 1 N H.S04 was investigated by using a nuctear microanalysis technique for the determination of 0" and 01* isotopes on the metal surface. It was established by Ozs tracing that the first monolayer of oxygen has a marked effect on the passivity of the metal. Further thickening of the film up to a maximum of about 5 monolayers seems to control the anodlc current by an ion-transfer mechanism. The total quantity of oxygen found on the samples after their removal from the solution is independent of the polarization potential, due probably to further oxidation in the atmosphere. R&sum&-Etude de la passivite du nickel dans H,SO, 1 N au moyen d'une technique nucl&aire de microanalyse, en vue de la discrimination des isotopes 0 l8 et 01% sur la surface metallique. 11 a ett6 etabli par le traceur 01* que la premiere couche monomol&culaire d'oxyg&ne a une influence mar x u&a sur la passiviti du m&al. De plus, 1'6paississement du film jusqu'a un maximum d'environ 5 couc es monomoleculaires, semble impliquer le contr6le du couraut anodique par un mecanisme de transfer-t ionique. La quantitb totale d'oxygene trouv& sur Ies &hantillons aprb leur separation de la solution cst ind+endante du potcntiel de polarisation, probablement du fait d'une oxydation ulterieure par l'atmosphere.