Magnetism and electronic structure in uranium systems with charge transfer

Abstract

The project is based on the recognition that magnetic and other electronic properties of U-based systems can be tuned, besides known factors as U-U spacing, also by a charge transfer between U and ligand states. This mechanism, which is most likely the reason for anomalously high ordering temperatures of U hydrides, should be operational also in pnictides (compounds with P, As, Sb, Bi). Existing data support this assumption. We intend to perform a broader experimental study of U-based hydrides and selected pnictides, synthesized both as a bulk and thin films. Determination of bulk properties will be accompanied by spectroscopies (XPS, UPS, BIS, XAS) reflecting the charge transfer. Advanced theoretical and computational techniques will be developed and implemented to capture and understand the variations of the ground state as well as development of spectra, which crucially reflect e-e correlations and different types of excitations. Thin film technique will be used to explore artificial structures, suitably combining high ordering temperatures and very strong spin-orbit interaction.