13C-labeling and NMR study of Mn12
作者： R.M Achey , P.L Kuhns , W.G Moulton , A.P Reyes , N.S Dalal
DOI: 10.1016/S0277-5387(01)00683-0
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摘要: Abstract The nanomagnet [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O, or Mn12, was studied by 13C NMR spectroscopy. sample 13C-labeled at the methyl carbon position, and magnetically aligned. spectrum generally consisted of four distinct peaks. peaks were assigned to positions in Mn12 lattice. Spin–lattice relaxation, T1, measurements revealed a minimum T1 about 60 K. A fit BPP (Bloembergen, Purcell, Pound) model with two relaxation modes suggests thermally activated behavior on either side T1. At lower temperature, activation energy is 64 K, which correlates barrier for electronic spin reorientation. higher 183 may correspond group rotation.
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