Seminar : “X-ray spectroscopy studies : successes and challenges in nano-magnetism”

Nieli Daffé, researcher at the Paul Scherrer Institute (Switzerland)

Wednesday October 26th / 11am 

Levisalles Room
Tower 42 Saint Bernard Level

Circular polarization-dependent X-ray absorption spectroscopy (XAS) in the soft X-ray energy range (⁓400 – 1800 eV) is a very efficient tool to investigate the magnetic properties of 3d transitions metals by excitations of 2p core electrons to 3d states (L2,3 edges). In this talk, three scientific cases will illustrate a few characteristics that makes this technique unique. Exploiting the element specificity and the direct access to 3d states, we have investigated the magnetic anisotropies in ferromagnetic core@shell nanoparticles, the magnetic couplings in binary ferrofluids as well as the light-induced electron transfer process in Fe/Co cyanometallate complexes. Through these examples, I will present valuable alternatives when the underlying sample environment, technique of deposition or physical process go beyond the current capabilities of the related experiments.

Rodrigue Lescouëzec