PhD n°6
Eligibility:
EU mobility rules apply. In principle, applicants can have any nationality and any current residence (although immigration rules apply, favoring
EU applicants). Candidates who have already been awarded a PhD degree are not eligible. In addition, candidates who have already spent more than 12 months in the Sweden within the last 3 years are not eligible (unless as part of a procedure for obtaining refugee status under the Geneva Convention).
Objectives:
Ce-based materials are used in a large variety of applications whereby the oxidation state of Ce and the localization degree of the Ce 4f state largely determine the material properties. Using materials informatics to analyse data sets for a large collection of compounds to search for trends in materials classes. The goal of this project is to derive a method which allows to classify existing Ce systems and derive descriptors for high throughput searches to identify new materials with tailored properties for different applications (e.g. magnetic, thermoelectric, catalytic). XPS and XAS are important tools for the analysis and will be calculated for the systems under investigation. The level of theory needed depends on the localization of the (f) electrons and must be determined in a first step.
Therefore, the following tasks will be addressed:
- Performing DFT calculations to get electronic structure and hybridization function for determination of localization.
- Determination of the XPS and XAS (XMCD) using first principles techniques based on density functional theory (DFT) and/or dynamical mean field theory (DMFT) or SPRKKR (for alloys).
- Extension of the Uppsala full-potential LMTO code RSPt such that d-f transitions (M4,5) edges can be handled (so far only p to d). Testing and comparison to available experimental spectra data
Expected Results:
- Extended and improved computer code RSPt to handle L and M edge spectra of correlated systems. (WP4)
- Derivation of suitable descriptors to be used in High throughput calculations/machine learning to identify new candidate phases with tailored properties. (WP4)
- Detailed insight in spin structure and electronic properties of newly predicted Ce-systems (WP1, WP2)
Planned secondment(s): 8 months
- Academic: UWB, Jan Minár; M15-M16; gain expertise in SPR- KKR for calculation of XAS/XMCD for disordered systems.
- Academic: DTU, K. Thygesen, M22-M23 machine learning techniques for analysis of the spectra, XAS
- Intersectoral: SCIENTA, A. Hahlin, M31-M34, Analysis of the state-of-the-art file formats used in spectroscopy in industry and academics
Enrolment in Doctoral degree(s):
DN: UU
Contact:
Heike Herper
heike.herper@physics.uu.se