Chris Grovenor oral presentation (PLEN-Mon)
Choosing between high resolution SIMS and Atom Probe Tomography to study key problems in 21st Century materials.
Materials Department - Oxford University, Parks Road, OX1 3PH Oxford, United Kingdom
Many materials being developed for 21st Century engineering applications are deliberately and carefully structured at the nanoscale, and present significant analytical problems when asking the question – what is the composition of my material at the nanometer scale? Similar problems arise when deciding how to study key degradation mechanisms in functional and structural materials, especially those that involve light elements like hydrogen that pose their own analytical challenges. Of course, instrument manufacturers are continually improving the specifications and capabilities of their products, and the development of new sample preparation techniques has revolutionised our ability to isolate the specific few cubic microns we want to analyse in a complex 3D microstructure. As these techniques become more widely available, it is becoming more important to select the right technique for the chosen sample or problem, rather than assume that ‘our’ technique is the correct choice for every experiment.
If the chemistry of the sample at the sub-micron scale is the focus of an experimental programme, we have many techniques to choose from, but for functional or structural materials many researchers will be considering the relative merits of various modes of electron microscopy, SIMS or Atom Probe Tomography. If the analytes of interest are present in bulk concentrations below about 10-4, the choice is often limited to SIMS and APT. This talk will present examples of comparative experiments using these powerful techniques on the same samples; drawn from the presenter’s experience in Oxford, and from the work of collaborating groups elsewhere. These examples will include high performance engineering alloys and nuclear materials, but will also comment on the use of these physical science techniques in the life and plant sciences where they are not often employed but can provide useful information hard to achieve by techniques more familiar to that community.