Developing the three dimensional Atom Probe
Research in the Department of Materials has led to major advances in Atom Probe microanalysis, a crucial technique used in the study and development of materials for a wide range of engineering applications.
Three-dimensional Atom Probes (or Atom Probe Tomography instruments as they are sometimes described) are vital to the study of engineering materials. They enable a sample to be evaporated atom by atom so that the detailed atomic-scale chemistry of the sample can be reconstructed in three dimensions. This technique is of huge importance in the design of steels, zirconium and tungsten alloys for future nuclear reactors, new aerospace and turbine alloys, and novel electronic materials. It allows a very detailed analysis of the exact chemical processes involved in corrosion or in-service degradation, generating information which cannot be gained by surface examination or through other techniques such as electron microscopy.
Research at Oxford has enabled significant advances in the performance and capability of the Atom Probe technique. Innovations developed and patented at Oxford by Materials researchers included designing and demonstrating the world’s first 3D instrument and increasing the data collection rate by a factor of more than 100. Subsequently they developed the idea of incorporating a reflectron lens or ‘energy mirror’ into the Atom Probe. This innovation made it easier to investigate in 3D the precise chemical composition of complex alloys and engineering materials not possible in earlier instrument designs.
These improvements in 3D Atom Probe technology made it possible for Oxford researchers to make significant advances in the study of engineering materials, applying the Atom Probe technique to a wide range of problems previously considered too challenging to solve. Publications from Oxford helped to establish the 3D Atom Probe as one of the most important new tools for understanding the structure and properties of modern engineering materials.
A spin-out company was formed to develop the first commercial versions of the 3D Atom Probe. The company received the Prince of Wales Award for Innovation, the DTI National Measurement Award and the International R & D 100 Award designation for its Energy Compensated Position Sensitive Atom Probe – the forerunner of all commercial Atom Probe instruments. The company was subsequently acquired by Amatek, and research and development at Oxford led directly to designs critical for the performance of the current market-leading instrument, the Ametek-CAMECA Local Electrode Atom Probe (LEAP).
Over the five-year period from 2008-2013, 45 LEAP systems with a value of $102M were sold worldwide, and these have made a major contribution to the development of many new engineering materials including thin-film solar cell technologies, new superalloys for power plants and integrated circuit technology. Atom Probe microanalysis has become a vital tool in the study of the changes in microstructure in reactor pressure vessel steels during prolonged irradiation, thereby contributing to the long-term safety of nuclear power stations.
‘The LEAP is not just important but it is an absolute breakthrough technology for materials engineering, it is essential for us, and the research by the University of Oxford has been at the absolute forefront here’ - Director and Head of Department: Max-Planck-Institut für Eisenforschung GmbH
Research funded by: The Royal Society, EPSRC, the EC, the US National Science Foundation, Kindbrisk Ltd, RoentDek GmbH, Kelkheim, FRG, Oxford Nanoscience Ltd, Alcan International.
Image courtesy of Professor Sergio Lozano-Perez, University of Oxford.