Freiburg 2024 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 15: Spectroscopy of Metal Clusters

MO 15.3: Vortrag

Mittwoch, 13. März 2024, 15:15–15:30, HS 3042

Magnetic nanodoping: cobalt doped silver clusters — •V. Zamudio-Bayer¹, K. Hirsch¹, L. Ma², K. De Knijf³, X. Xu⁴, A. Ławicki¹, A. Terasaki⁵, P. Ferrari³, B. von Issendorff⁶, P. Lievens³, W.A. de Heer⁷, J.T. Lau^1,6, and E. Janssens³ — ¹HZB, DEU — ²TCNN, CHN — ³KU Leuven, BEL — ⁴UNL, USA — ⁵Kyushu U., JPN — ⁶U. Freiburg, DEU — ⁷Georgia Tech, USA

The magnetic properties of neutral and charged silver metal clusters with a magnetic cobalt atom impurity were investigated experimentally by exploiting the complementary methods of Stern-Gerlach cluster beam deflection and XMCD action spectroscopy and are accompanied by DFT calculations and charge transfer multiplet simulations [Phys. Rev. Research 5, 033103 (2023)]. The influence of the number of valence electrons and the consequences of impurity encapsulation were addressed in free size-selected, singly cobalt-doped silver clusters CoAg_n^0,+ (n = 2–15). Encapsulation of the dopant facilitates the formation of delocalized electronic shells with complete hybridization of the impurity 3d- and the host 5s-derived orbitals, which results in impurity valence electron delocalization, effective spin relaxation, and a low-spin ground state. Doped clusters with more than nine silver atoms are low-spin systems independent of their charge state, coincident with the increase in stability and decrease in reactivity of endohedrally doped silver clusters. In the exohedral cluster size range, spin pairing in the free electron gas formed by the silver 5s electrons is the dominating driving force determining the local 3d occupation of the impurity and thus the cluster’s spin multiplicity.

Keywords: clusters; ion trap; Stern-Gerlach; magnetism; spin multiplicity