ABSTRACT
References ............................................................................................................ 165
5.1 INTRODUCTION
Data on the chemistry and structure at the liquid/solid interface are necessary to
understand and predict the corrosion behavior of metals and alloys in aqueous
solutions and to improve the corrosion resistance of metallic materials in corrosive
environments. Surface sensitive analysis techniques such as x-ray photoelectron
spectroscopy (XPS), Auger electron spectroscopy (AES), secondary ion mass spec-
trometry (SIMS), nuclear reaction analysis (NRA), infrared reflection absorption
spectroscopy (IRRAS), described in this book, are very useful to obtain data on the
chemical composition of corroded surfaces. The panel of techniques that can be used
to obtain structural data is more restricted. This is, in part, due to the difficulty of any
structural analysis of very thin films on often rough substrates, using reflection high-
energyelectrondiffraction (RHEED)andgrazing incidencex-raydiffraction (GXRD),
or low-energy electron diffraction (LEED), which is restricted to the ex situ ultrahigh
vacuum (UHV) analysis of single-crystal surfaces. The advent of near-field microsco-
pies (STM, scanning tunneling microscopy, and AFM, atomic force microscopy) in
the 1980s has opened up new prospects in this field. Direct imaging of the surface
structure on a scale ranging from a few micrometers down to atomic or molecular
resolution can now be performednot only in ex situ (UHV or air) but most relevantly in
in situ conditions. Moreover, time-resolved imaging allows the investigation of the
dynamics of the structure modifications produced by corrosion processes.
