Identifying the organisation of electrons in matter.
Electronic structure defines how electrons organise within matter. It provides vital insights into the origin of physical properties down to the atomic scale. Quantifying electronic structure experimentally can be used to define atomic electron configurations, oxidation state, the type of chemical bonds, the coordination symmetry of bound atoms and the quantum spin and orbital contributions to magnetic properties.
Our research group specialises in the application of both X-ray and inelastic neutron spectroscopies for the study of electronic structure. We apply a broad range of X-ray techniques including X-ray absorption near-edge fine structure (XANES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). We apply dichroism for some of these methods, including X-ray magnetic circular dichroism (XMCD) and X-ray linear dichroism. It is an important part of our research to back experimental results with theoretical simulations. This enables us to obtain a fundamental understanding of experimental sensitivities to electronic structure and facilitates precise quantification of physical properties.
We utilise atomic multiplet theory, time-dependent density functional theory and ab. initio. quantum chemistry methods to simulate spectra and identify precise descriptions of electronic structure.
- Myron Huzan
- Nathan Alcock (PhD)
- Rasmus Tang Christiansen (PhD)
- Zhi Bo Qi (DLS PhD)
- Saifeldin Siddeeg (MSc)
X-ray absorption spectroscopies are ideally suited for accessing electronic structure since by tuning the x-ray energy it is possible to measure the excitation of core-electrons into the lowest energy unoccupied orbitals.
Since the absorption edge energy is specific for any given element, element-specific electronic structure can be obtained in crystalline and non-crystalline environments. X-ray absorption spectroscopy can therefore provide important information concerning the electronic and geometric structure of an analyte in solid, liquid or even gaseous forms.
Combining X-ray absorption with emission spectroscopy makes it possible to measure both the lowest energy unoccupied orbitals and the highest energy occupied orbitals, providing a holistic picture of the frontier molecular orbitals or Fermi level.
Inelastic neutron spectroscopy
Neutrons have a quantum spin of a half but carry no charge and are therefore highly penetrating in matter. We apply inelastic neutron scattering to study the spin dynamics of molecular-based magnetic compounds.
Specific projects currently underway include:
- electronic structure and magnetisation dynamics of single-ion dopants in solid-state crystals
- study of spin dynamics within molecules that exhibit valence delocalisation
- characterisation of molecular-based switchable magnetism
- determination of f-block element electronic structure and bonding
- unravelling the mysteries of f-block electronic structure