TY - JOUR
T1 - Magnetic moments of chromium-doped gold clusters
T2 - The anderson impurity model in finite systems
AU - Hirsch, K.
AU - Zamudio-Bayer, V.
AU - Langenberg, A.
AU - Niemeyer, M.
AU - Langbehn, B.
AU - Möller, T.
AU - Terasaki, A.
AU - Issendorff, B. V.
AU - Lau, J. T.
N1 - Publisher Copyright:
© 2015 American Physical Society.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2015/2/25
Y1 - 2015/2/25
N2 - The magnetic moment of a single impurity atom in a finite free electron gas is studied in a combined x-ray magnetic circular dichroism spectroscopy, charge transfer multiplet calculation, and density functional theory study of size-selected free chromium-doped gold clusters. The observed size dependence of the local magnetic moment can be understood as a transition from a local moment to a mixed valence regime. This shows that the Anderson impurity model essentially describes finite systems even though the discrete density of states introduces a significant deviation from a bulk metal, and the free electron gas is only formed by less than 10 electrons. Electronic shell closure in the gold host minimizes the interaction of localized impurity states with the confined free electron gas and preserves the magnetic moment of 5μB fully in CrAu2+ and almost fully in CrAu6+. Even for open-shell species, large local moments are observed that scale with the energy gap of the gold cluster. This indicates that an energy gap in the free electron gas stabilizes the local magnetic moment of the impurity atom.
AB - The magnetic moment of a single impurity atom in a finite free electron gas is studied in a combined x-ray magnetic circular dichroism spectroscopy, charge transfer multiplet calculation, and density functional theory study of size-selected free chromium-doped gold clusters. The observed size dependence of the local magnetic moment can be understood as a transition from a local moment to a mixed valence regime. This shows that the Anderson impurity model essentially describes finite systems even though the discrete density of states introduces a significant deviation from a bulk metal, and the free electron gas is only formed by less than 10 electrons. Electronic shell closure in the gold host minimizes the interaction of localized impurity states with the confined free electron gas and preserves the magnetic moment of 5μB fully in CrAu2+ and almost fully in CrAu6+. Even for open-shell species, large local moments are observed that scale with the energy gap of the gold cluster. This indicates that an energy gap in the free electron gas stabilizes the local magnetic moment of the impurity atom.
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U2 - 10.1103/PhysRevLett.114.087202
DO - 10.1103/PhysRevLett.114.087202
M3 - Article
AN - SCOPUS:84924130773
SN - 0031-9007
VL - 114
JO - Physical Review Letters
JF - Physical Review Letters
IS - 8
M1 - 087202
ER -