John Griffin is a lecturer in Materials Chemistry at Lancaster University. His research interests concern the development of solid-state NMR (SSNMR) methods to solve problems in materials science, with a particular focus on energy materials. During his PhD at the University of Warwick, he developed high-resolution NMR methods for the study of pharmaceuticals. He then joined the group of Prof. Sharon Ashbrook at the University of St Andrews to carry out postdoctoral research in combining advanced NMR experiments with first-principles DFT calculations to characterise disorder and dynamics. This was followed by a postdoctoral position in the group of Prof. Clare Grey, FRS, at the University of Cambridge, where he developed in situ NMR methods for the elucidation of supercapacitor charging mechanisms.
An Atom’s Eye View: Studying Structure and Function in Materials using Nuclear Magnetic Resonance Spectroscopy
Solid-state nuclear magnetic resonance (NMR) is one of the most powerful probes of atomic-level structure and is applicable to a wide range of systems across chemistry and materials science. While this technique is most commonly applied to favourable nuclei such as 1H, and 13C, in principle almost all of the elements in the periodic table are accessible to study by NMR, and in many cases the nuclear spin properties of more ‘exotic’ nuclei can yield detailed information that cannot be obtained by other analytical techniques. Recent years have seen many advances in technology and hardware, and also in solid-state NMR methodology, meaning that experiments that were previously unfeasible can now be routinely applied. Of great importance has also been the introduction of computational codes for the efficient and accurate calculation of NMR parameters for periodic solids, which provide the possibility to test and verify model structures against experimental results.
This presentation will illustrate some of the structural information that can be obtained for a range of complex materials including minerals, proton-conducting oxides and organic semiconductors. For these systems, advanced NMR experiments performed on nuclei such as 17O, 19F and 31P combined with theoretical calculations on model structures provide detailed pictures of atomic-level structure, dynamics and disorder within the material. The application of NMR as an in situ approach will also be described, whereby experiments performed on a working energy storage device enable the charging mechanism to be fully characterised.