We investigate the phonon-induced relaxation dynamics in the Fe7 magnetic molecule, which is made of two Fe3+ triangles bridged together by a central Fe3+ 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/T1. 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/T1 data we also take into account the wipeout effect at low temperatures.
Relaxation dynamics in a Fe7 nanomagnet / Garlatti, E.; Carretta, S.; Santini, P.; Amoretti, G.; Mariani, Manuel; Lascialfari, A.; Sanna, Samuele; Mason, K.; Chang, J.; Tasker, P.; Brechin, E. K.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 87:(2013), pp. 054409.1-054409.7. [10.1103/PhysRevB.87.054409]
Relaxation dynamics in a Fe7 nanomagnet
MARIANI, MANUEL;SANNA, SAMUELE;
2013
Abstract
We investigate the phonon-induced relaxation dynamics in the Fe7 magnetic molecule, which is made of two Fe3+ triangles bridged together by a central Fe3+ 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/T1. 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/T1 data we also take into account the wipeout effect at low temperatures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.