Spin Dynamics and Quantum Tunneling in Molecular Magnet Fe8
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概要
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Spin dynamics and quantum tunneling of magnetization in single crystals of the molecular magnet Fe8 have been studied by ^1H-NMR experiment. The ground state of Fe8 has a total spin S = 10. NMR spectra show that below about 3K the iron spins freeze in the double potential wells separated with the energy barrier of 25K, while they are superparamagnetic above that temperature. The spin lattice relaxation rates above 400 mK are strongly temperature dependent. The relaxation is dominated by the thermal transition of the iron spin states between the energy levels discretely separated by the single ion-type anisotropy. The rates become to be temperature independent and very long over 100 sec below 300 mK. In this temperature range we have observed the fast recovery of ^1H-NMR spectra at the level crossing fields. This phenomenon is caused by the resonant quantum tunneling of the iron magnetization and is analyzed by the Landau-Zener transition.
- 理論物理学刊行会の論文
- 2002-06-28
著者
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MAEGAWA Satoru
Graduate School of Human and Environmental Studies, Kyoto University
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Maegawa Satoru
Graduate School Of Human And Environmental Studies Kyoto University
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Ueda Miki
Graduate School Of Human And Environmental Studies Kyoto University
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