Development of DFT methods to study atomic structure and pressure effects in f- electron materials
Rare earth materials are in increasing demand making good modelling of their electrons important for further development.
The elements have similar chemistry owing to common valence electronic structure but varying numbers of nearly bound f-electrons, which determine magnetic properties. Using recent advances in modelling alloys and f-electron effects in magnets, this project will develop Density Functional Theory methodology for multicomponent lanthanide materials.
We will study, for example, how application of pressure causes the f-electrons in cerium-rich alloys to delocalise and join the valence electrons triggering a dramatic change in properties.
The project will explore building machine learning interatomic potentials for further modelling.
Supervisors
Primary: Prof. Julie Staunton, Physics
Dr Albert Bartok-Partay, Engineering/Physics
A transcript of the video is available by clicking this link - transcript opens in another windowLink opens in a new window
The most widely used computational implementation of Density functional theory employs a plane-wave basis coupled with pseudopotentials. Whilst immensely successful for materials modelling, its calculations can become computationally prohibitive for studying multicomponent systems with large supercells. For materials where the f-electron effects are important, such as those containing lanthanide elements La, Ce, …, Lu, there is the additional challenge of describing strong f-electron correlations adequately. For Ce materials there is the further complication that the single f-electron per Ce atom can be delocalised, hence describable with standard DFT exchange and correlation, or localised and subject to strong correlations. This aspect and the local structural and compositional environment of the lanthanide atoms are interdependent. Green’s function multiple scattering (KKR) codes can provide alternative routes to address these challenges. They include strong f-electron correlation and relativistic effects and use effective medium methods, (coherent potential approximation) for fast averaging over atomic configurations.
Given recent advances in modelling the atomic arrangements of multicomponent alloys [1] and the f-electron effects in rare earth -transition metal permanent magnets [2], it is timely to develop this methodology for multicomponent lanthanide systems. Such an advance will enable, for example, a study of how modest concentration levels of impurities are arranged and affect the properties of Ce, under pressure, or the phase diagram of the high entropy alloy GdTbDyHo or even obtaining insight into high stability of the primary commercial form of rare earth metals, i.e. Misch metal (50% Cerium, 25% La, 15% Nd and 10% other rare-earth metals and iron).
[1] C. D. Woodgate et al., Physical Review Materials 7 (5), 053801, (2023).
[2] C. E. Patrick and J. B. Staunton, Physical Review B 97 (22), 224415, (2018).
Supported in part by AWE (Patrick Hollebon, James Harris).
How to apply
This is a fully-funded 4-year PhD position based in the HetSys Centre for Doctoral Training at the University of Warwick. All applications must be made through the University's postgraduate application form with a deadline of 20 January 2025. Please see our How to ApplyLink opens in a new window page for further details on the application process. For further information about student funding, the integrated HetSys training programme and what life is like in the HetSys CDT, please visit the Study with Us page.
Please note that due to the nature of our project partner's work, nationality restrictions apply to applications for this project.
If you need guidance on this please email hetsys@warwick.ac.uk
.