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Atomic transport mechanisms in thin oxide films grown on zirconium by thermal oxidation, as-derived from 18O-tracer experiments / G. Bakradze in Acta materialia, Vol. 59 N° 20 (Décembre 2011) 

Public ISBD [article]  in Acta materialia > Vol. 59 N° 20 (Décembre 2011) . - pp. 7498–7507 Titre : Atomic transport mechanisms in thin oxide films grown on zirconium by thermal oxidation, as-derived from 18O-tracer experiments Type de document : texte imprimé Auteurs : G. Bakradze, Auteur ; L.P.H. Jeurgens, Auteur ; T. Acartürk, Auteur Année de publication : 2012 Article en page(s) : pp. 7498–7507 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Oxidation  Mechanism  Nanocrystalline  films  Zirconium  Time-of-flight  secondary  ion  mass-spectrometry Résumé : Two-stage oxidation experiments using 16O and 18O isotopes were performed to reveal the governing atomic transport mechanism(s) in thin (thickness <10 nm) oxide films grown during the initial stages of dry thermal oxidation of pure Zr at 450 K. To this end, bare (i.e. without a native oxide) Zr(0 0 0 1) and Zr single-crystalline surfaces were prepared under ultra-high vacuum conditions by a cyclic treatment of alternating ion-sputtering and in vacuo annealing steps. Next, the bare Zr surfaces were oxidized at 450 K and at pO2 = 1 × 10−4 Pa, first in 16O2(g) and subsequently in 18O2(g). The 18O-tracer depth distributions in the oxide films were recorded by time-of-flight secondary ion mass spectrometry. It was concluded that the early stage of the oxidation process is governed by oxygen transport to the metal/oxide interface through the lattice and along the grain boundaries of the nanosized oxide grains whereas, on continuing oxidation, only oxygen lattice transport controls the oxidation process. An oxide-film growth mechanism is proposed. ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645411006124 [article] Atomic transport mechanisms in thin oxide films grown on zirconium by thermal oxidation, as-derived from 18O-tracer experiments [texte imprimé] / G. Bakradze, Auteur ; L.P.H. Jeurgens, Auteur ; T. Acartürk, Auteur . - 2012 . - pp. 7498–7507. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 59 N° 20 (Décembre 2011) . - pp. 7498–7507 Mots-clés : Oxidation  Mechanism  Nanocrystalline  films  Zirconium  Time-of-flight  secondary  ion  mass-spectrometry Résumé : Two-stage oxidation experiments using 16O and 18O isotopes were performed to reveal the governing atomic transport mechanism(s) in thin (thickness <10 nm) oxide films grown during the initial stages of dry thermal oxidation of pure Zr at 450 K. To this end, bare (i.e. without a native oxide) Zr(0 0 0 1) and Zr single-crystalline surfaces were prepared under ultra-high vacuum conditions by a cyclic treatment of alternating ion-sputtering and in vacuo annealing steps. Next, the bare Zr surfaces were oxidized at 450 K and at pO2 = 1 × 10−4 Pa, first in 16O2(g) and subsequently in 18O2(g). The 18O-tracer depth distributions in the oxide films were recorded by time-of-flight secondary ion mass spectrometry. It was concluded that the early stage of the oxidation process is governed by oxygen transport to the metal/oxide interface through the lattice and along the grain boundaries of the nanosized oxide grains whereas, on continuing oxidation, only oxygen lattice transport controls the oxidation process. An oxide-film growth mechanism is proposed. ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645411006124