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Direct measurement of the tunneling rate of the magnetization in Fe8 via 57Fe nuclear spin-lattice relaxation by strong collision

S. H. Baek·F. Borsa·Y. Furukawa·Y. Hatanaka·S. Kawakami·K. Kumagai
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Abstract

$^{57}$Fe and $^1$H relaxation measurements have been performed in single crystal and oriented powder of enriched $^{57}$Fe8 molecular cluster in the temperature range 0.05--1.7 K in zero external field and with small perturbing longitudinal field ($< 1$ T). On the basis of the experimental results it is argued that in zero external field the nuclear spin-lattice relaxation ($1/T_1$) mechanism is driven by a strong collision mechanism whereby $1/T_1$ is a direct measure of the incoherent tunneling probability in the low lying magnetic energy states of the molecular nanomagnet. The approximate value of the effective tunneling rate vs $T$ and $H$ derived directly from $1/T_1$ is shown to be consistent with theoretical estimates based on known parameters of the Hamiltonian.

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S. H. Baek, F. Borsa, Y. Furukawa, Y. Hatanaka, S. Kawakami, K. Kumagai. 2004-10-28. Direct measurement of the tunneling rate of the magnetization in Fe8 via 57Fe nuclear spin-lattice relaxation by strong collision. https://arxiv.org/abs/cond-mat/0409672

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