TY - JOUR
T1 - NMR as a probe of the relaxation of the magnetization in magnetic molecules
AU - Santini, P.
AU - Carretta, S.
AU - Liviotti, E.
AU - Amoretti, G.
AU - Carretta, P.
AU - Filibian, M.
AU - Lascialfari, A.
AU - Micotti, E.
PY - 2005/2/25
Y1 - 2005/2/25
N2 - We investigate the time autocorrelation of the molecular magnetization M(t) for three classes of magnetic molecules (antiferromagnetic rings, grids, and nanomagnets), in contact with the phonon heat bath. For all three classes, we find that the exponential decay of the fluctuations of M(t) is characterized by a single characteristic time τ(T, B) for not too high temperature T and field B. This is reflected in a nearly single-Lorentzian shape of the spectral density of the fluctuations. We show that such fluctuations are effectively probed by NMR, and that our theory explains the recent phenomenological observation by Back et al. [Phys. Rev. B 70, 134434 (2004)] that the Larmor-frequency dependence of 1/T1] data in a large number of AFM rings fits to a single-Lorentzian form.
AB - We investigate the time autocorrelation of the molecular magnetization M(t) for three classes of magnetic molecules (antiferromagnetic rings, grids, and nanomagnets), in contact with the phonon heat bath. For all three classes, we find that the exponential decay of the fluctuations of M(t) is characterized by a single characteristic time τ(T, B) for not too high temperature T and field B. This is reflected in a nearly single-Lorentzian shape of the spectral density of the fluctuations. We show that such fluctuations are effectively probed by NMR, and that our theory explains the recent phenomenological observation by Back et al. [Phys. Rev. B 70, 134434 (2004)] that the Larmor-frequency dependence of 1/T1] data in a large number of AFM rings fits to a single-Lorentzian form.
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U2 - 10.1103/PhysRevLett.94.077203
DO - 10.1103/PhysRevLett.94.077203
M3 - Article
AN - SCOPUS:18144367327
VL - 94
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 7
M1 - 077203
ER -