Theme 1 colloquium: "Unusual magnetism at sub-nanoscale: magnetic deflection experiments of small clusters” (Lecture)
- Tuesday 2 May 2017Add to my calendar
- from 16:00
prof. Andrei Kirilyuk
Here I will review our recent experiments on magnetism of small gas-phase clusters. The classical Stern-Gerlach deflection technique is used for the experiments, with some modifications. First, I discuss the specifics of such experiments with respect to the atomic beam deflections, and the treatment of the deflection profiles. Then, all the studied cases have shown a very unusual magnetic behavior, as compared to their bulk. Thus, rare-earth clusters show a complete change of the magnetic exchange mechanism, that becomes also strongly dependent on the cluster size. Unlike the bulk, the exchange is shown to be driven by finite size effects and is varying between super- and double exchange. Then, rhodium, a non-magnetic metal in the bulk, becomes magnetic dielectric in the cluster form, with both magnetic and electric dipole moments present. Vanadium and niobium clusters show in most case a blocking of spin-lattice coupling, following the Kramer's theorem.
I will also discuss possible extensions of these experiments in a combination with resonant magnetic and lattice excitations at FELIX.