  We present an assessment of a multi-method approach based on ion beam
analysis to obtain high-resolution depth profiles of the total chemical
composition of complex alloy systems. As a model system we employ an alloy
based on several transition metals and containing light species. Samples have
been investigated by a number of different ion-beam based techniques, i.e.,
Rutherford Backscattering Spectrometry, Particle-Induced X-ray Emission,
Elastic Backscattering Spectrometry and Time-of-Flight/Energy Elastic Recoil
Detection Analysis. Sets of spectra obtained from these different techniques
were analyzed both independently and following an iterative and self-consistent
approach yielding a more accurate depth profile of the sample, including both
metallic heavy constituents (Cr, Fe and Ni) as well as the rather reactive
light species (C, O) in the alloy. A quantitative comparison in terms of
achievable precision and accuracy is made and the limitations of the single
method approach are discussed for the different techniques. The multi-method
approach is shown to yield significantly improved and accurate information on
stoichiometry, depth distribution, and thickness of the alloy with the
improvements being decisive for a detailed correlation of composition to the
material properties such as corrosion strength. The study also shows the
increased relative importance of experimental statistics for the achievable
accuracy in the multi-method approach.
