  Oxide passive films are a key for the durability of metals and alloys
components as well as a central issue in corrosion science and engineering.
Herein, we discuss current developments of the nanometer and sub-nanometer
scale knowledge of the barrier properties and adsorption properties of passive
oxide films brought by recent model experimental and theoretical
investigations. The discussed aspects include (i) the chromium enrichment and
its homogeneity at the nanoscale in passive films formed on Cr-bearing alloys
such as stainless steel, (ii) the corrosion properties of grain boundaries in
early intergranular corrosion before penetration and propagation in the grain
boundary network, and (iii) the interaction of organic inhibitor molecules with
incompletely passivated metallic surfaces. In all three cases, key issues are
highlighted and future developments that we consider as most relevant are
identified.
