Published January 1, 2002 | Version v1
Journal article

1H NMR investigation of the spin dynamics of the spin-frustrated trinuclear Fe cluster (NH4)[Fe3(μ3-OH)(H2L)3(HL)3] (H3L=orotic acid)

  • 1. Department of Physics, National Technical University of Athens, 15780 Athens (Greece)
  • 2. Department of Materials Science, University of Patras, 26500 Patras (Greece)
  • 3. Institute of Materials Science, National Center for Scientific Research 'Demokritos', 15310 Athens (Greece)

Description

Proton nuclear-magnetic-resonance (NMR) measurements have been performed in the cluster (NH4)[Fe3(μ3-OH)(H2L)3(HL)3] (H3L=orotic acid) in order to investigate the electron spin dynamics of the Fe trinuclear unit. The proton NMR spectra and spin-lattice relaxation times T1 have been measured at temperatures between 3 K and room temperature. The 1/T1 rate exhibits a broad maximum around 50 K, which is attributed to slow local-field fluctuations of the electronic spin system of the order of the Larmor period, associated with magnetic excitations between the discrete low-lying energy levels of the cluster. The observation and relaxation analysis of the 1/T1 maximum provide an independent measurement of the energy difference between the ground and the first-excited state of the trinuclear unit and corroborates the results of previous static susceptibility measurements

Additional details

Identifiers

Publishing Information

Journal Title
Physical Review. B, Condensed Matter and Materials Physics
Journal Volume
65
Journal Issue
1
Journal Page Range
p. 014412-014412.6
ISSN
1098-0121

Optional Information

Notes
(c) 2001 The American Physical Society