Probing f-electron Physics at Extreme Densities

The physical properties of the lanthanide (4f) and actinide (5f) elements (Ce-Lu and Th-Lr) vary dramatically as one traverses the groups from low-Z to high-Z. The properties of any one metal can be changed in a similar manner by the application of pressure, and many of these elements undergo a sequence of structural phase transitions accompanied by changes in electronic structure. We have recently made significant progress in unravelling the complex structural sequences seen in Pr and Eu under pressure at room temperature (both of which were PhD projects), and now plan to extend these studies to very much higher pressures and temperatures.

The project will involve diamond anvil cell experiments at synchrotron sources in the UK (Diamond), France (ESRF) and Germany (Petra-III), and may also involve dynamic-compression studies at laser sources in the UK and US. An exciting new development in DAC research is the utilisation of X-ray Free Electron Lasers (XFELs), such as the European-XFEL (XFEL.EU), to make dynamic diffraction measurements at P-T conditions previously unattainable. We expect this project to make pioneering measurements using this technique.