AVS 61st International Symposium & Exhibition
    Conservation Studies of Heritage Materials Focus Topic Friday Sessions
       Session CS-FrM

Paper CS-FrM10
The Application of Advanced Surface Analysis Techniques to the Study of Museum-Based Problems

Friday, November 14, 2014, 11:20 am, Room 313

Session: Conservation Studies of Modern Heritage Materials 3
Presenter: David S. McPhail, Imperial College London, UK
Correspondent: Click to Email
Museum materials are often (but not always) relatively stable and inert and the changes that take place to their appearance over time can be so slow as to be essentially imperceptible. For example a materials surface decaying at the rate of 1 nm per day requires approximately three millennia to form a 1 mm crust (assuming linear kinetics). It follows that extremely sensitive analytical instruments with very high sensitivity and resolution are required to measure these ultra-slow surface processes. It is interesting, therefore, that the very latest analytical tools developed primarily to characterise the very latest generation of modern materials such as nanomaterials and semiconductor quantum wells, are also very well suited for the study of the surfaces of historic and pre-historic materials.

In this talk I will show how techniques such as Secondary Ion Mass Spectrometry (SIMS), Focused-Ion Beam SIMS (FIB-SIMS) and Low Energy Ion Scattering (LEIS) can be used to determine the mechanisms and kinetics of processes such as oxidation, diffusion, corrosion and ion exchange at and near the surfaces of a variety of materials from museum collections. The materials will include glass, metals and ceramics. These analytical techniques can also be used to look at the changes that occur to surfaces as a result of cleaning interventions and can be used to look at how the surfaces becomes re-contaminated over time after cleaning interventions. Being ion-beam based UHV techniques they form the latter parts of any analytical hierarchy. These ion-beam based techniques can exploit stable isotope exchange protocols using ions such as D and O18 to aid the analysis.

There is of course a tension between conservation science and surface analysis as surface analysts like to sample objects and use techniques that consume the object – this is not very welcome by the museum community for obvious reasons. I will discuss this issue and introduce approaches to sampling that might be tolerable.