We investigate the phonon-induced relaxation dynamics in the Fe 7 magnetic molecule, which is made of two Fe 3 + triangles bridged together by a central Fe 3 + ion. The competition between different antiferromagnetic exchange interactions leads to a low-spin ground state multiplet with a complex pattern of low-lying excited levels. We theoretically investigate the decay of the time correlation function of molecular observables, such as the cluster magnetization, due to the spin-phonon interaction. We find that more than one time contributes to the decay of the molecular magnetization. The relaxation dynamics is probed by measurements of the nuclear spin-lattice relaxation rate 1 /T 1 . The interpretation of these measurements allows the determination of the magnetoelastic coupling strength and to set the scale factor of the relaxation dynamics time scales. In our theoretical interpretation of 1 /T 1 data we also take into account the wipeout effect at low temperatures
Relaxation dynamics in a Fe7 nanomagnet / E. Garlatti, S. Carretta, P. Santini, G. Amoretti, M. Mariani, A. Lascialfari, S. Sanna, K. Mason, J. Chang, P. Tasker, E. K. Brechin. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 87:5(2013), pp. 054409.1-054409.7. [10.1103/PhysRevB.87.054409]
Relaxation dynamics in a Fe7 nanomagnet
E. Garlatti;A. Lascialfari;
2013
Abstract
We investigate the phonon-induced relaxation dynamics in the Fe 7 magnetic molecule, which is made of two Fe 3 + triangles bridged together by a central Fe 3 + ion. The competition between different antiferromagnetic exchange interactions leads to a low-spin ground state multiplet with a complex pattern of low-lying excited levels. We theoretically investigate the decay of the time correlation function of molecular observables, such as the cluster magnetization, due to the spin-phonon interaction. We find that more than one time contributes to the decay of the molecular magnetization. The relaxation dynamics is probed by measurements of the nuclear spin-lattice relaxation rate 1 /T 1 . The interpretation of these measurements allows the determination of the magnetoelastic coupling strength and to set the scale factor of the relaxation dynamics time scales. In our theoretical interpretation of 1 /T 1 data we also take into account the wipeout effect at low temperaturesPubblicazioni consigliate
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