J. Phys. IV France 12 (2002) Pr8-155
DOI: 10.1051/jp4:20020330

Analysis of the stability of native oxide films at liquid lead/metal interfaces

C. Lesueur¹, D. Chatain¹, C. Bergman², P. Gas¹ and F. Baque<sup>3

1</sup>  Centre de Recherche sur les Mécanismes de la Croissance Cristalline, CNRS, Campus de Luminy, Case 913, 13288 Marseille cedex 9, France
²  Laboratoire de Matériaux et Microélectronique de Provence, Faculté de Saint-Jerôme, 13397 Marseille, France
³  CEA/Cadarache, Departement d'Etudes de Réacteurs, 13108 Saint-Paul-lez-Durance, France

Abstract
The interface between liquid lead and different metallic solids (pure metals : AI, Fe and Ni, and T91 steel) was investigated below 400°C under ultrahigh vacuum (UHV) by wetting experiments. The aim was to check the physical stability of native oxide films grown at the surface of the substrates, along a contact with liquid lead. Two types of metallic substrates were used : i) conventional bulk polycrystals, and ii) nanocrystalline films obtained by e-beam evaporation under UHV. The actual contact between liquid lead and the solid substrates was achieved by preparing lead drops in-situ. Wetting experiments were performed using sessile drop and/or liquid bridge methods. Fresh solid surfaces and former liquid/solid interfaces can be explored by squeezing and stretching a liquid lead bridge formed between two parallel and horizontal substrates. It is shown that the contact with liquid lead produces the detachment of the native oxide films grown on the metallic solids. It is concluded that if oxide coatings are needed to protect a metallic solid from attack by liquid lead, they should be self-renewable.

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