Rebecca Nicholls
Department of Materials
University of Oxford, UK
<rebecca.nicholls@materials.ox.ac.uk>
Professor Rebecca Nicholls has an MSci from the University of Cambridge, where she studied Natural Sciences. After a DPhil in Materials Science at the University of Oxford, she worked as a postdoc using electron microscopy to investigate a variety of materials from doped graphene to zirconia. Rebecca is now an Associate Professor and EPSRC Research Fellow in the Department of Materials at Oxford University. Her work focuses on the structure and bonding of materials at the atomic scale, bridging the gap between experiment and theory. She is one of the authors of the OptaDOS code and now works on interpreting X-ray data as well as data from electrons. Rebecca’s current research interests include predicting the vibrational spectra that can now be measured with the electron microscope and understanding defects in rare earth superconductors.
Lecture 26: Rebecca Nicholls
Phonon vibrations probed using the electron microscope
Rebecca Nicholls
Department of Materials
University of Oxford, UK
<rebecca.nicholls@materials.ox.ac.uk>
Recent advances in hardware mean we can now probe phonon vibrations in an electron microscope, giving us access to spectra with previously unprecedented spatial resolution and having the benefit of atomically resolved chemical analysis within the same instrument. Interpreting the spectra containing the signal from phonon vibrations is not always trivial, and simulation can be a vital part of maximising the information extracted from the data. There are several different theoretical approaches to simulating spectra, and this presentation will focus on modelling spectra from first principles. I will discuss the development of the theory and why spectra obtained in different experimental geometries (impact and aloof modes) require different theoretical approaches.