Publications (3)0 Total impact
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V. O. Garlea,
S. E. Nagler,
J. L. Zarestky,
C Stassis,
D. Vaknin,
P Kogerler,
D. F. McMorrow,
C. Niedermayer,
D. A. Tennant,
B. Lake,
Y Qiu, M Exler,
J. Schnack,
M Luban
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ABSTRACT: We report cold-neutron inelastic neutron scattering measurements on deuterated samples of the giant polyoxomolybdate magnetic molecule {Mo72Fe30}. The 30 s = 5/2 Fe+3 ions occupy the vertices of an icosidodecahedron, and interact via antiferromagnetic nearest neighbor coupling. The measurements reveal a band of magnetic excitations near E ~ 0.6 meV. The spectrum broadens and shifts to lower energy as the temperature is increased, and also is strongly affected by magnetic fields. The results can be interpreted within the context of an effective three-sublattice spin Hamiltonian.
06/2005;
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VO Garlea,
SE Nagler,
JL Zarestky,
C Stassis,
D. Vaknin,
P Kogerler,
D McMorrow,
C. Niedermayer,
DA Tennant,
B. Lake,
Y Qiu, M Exler,
J. Schnack,
M Luban
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VO Garlea,
SE Nagler,
JL Zaretsky,
C Stassis,
D Vankin,
P. Kögerler,
D McMorrow,
C. Niedermayer,
A Tennant,
B. Lake,
Y Qiu, M Exler,
M Luban
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[hide abstract]
ABSTRACT: Low temperature inelastic neutron scattering studies have been performed to characterize the low energy magnetic excitation spectrum of the magnetic nanomolecule Mo72Fe30. This unique highly symmetric cluster features spin frustration and is one of the largest discrete magnetic molecules studied to date by inelastic neutron scattering. The 30 s=5/2 FeIII ions, embedded in a spherical polyoxomolybdate molecule, occupy the vertices of an icosidodecahedron and are coupled via nearest-neighbor antiferromagnetic interactions. The overall energy scale of the excitation and the gross features of the temperature dependence of the observed neutron scattering are explained by a quantum model of the frustrated spin cluster. However, no satisfactory theoretical explanation is yet available for the observed magnetic field dependence.
