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Slow Magnetic Relaxation Induced by a Large Transverse Zero-Field Splitting in a MnIIReIV(CN)2 Single-Chain Magnet
journal contribution
posted on 2012-05-02, 00:00 authored by Xiaowen Feng, Junjie Liu, T. David Harris, Stephen Hill, Jeffrey R. LongThe model compounds (NBu4)2[ReCl4(CN)2] (1), (DMF)4ZnReCl4(CN)2 (2), and [(PY5Me2)2Mn2ReCl4(CN)2](PF6)2 (3) have been synthesized to probe
the origin
of the magnetic anisotropy barrier in the one-dimensional coordination
solid (DMF)4MnReCl4(CN)2 (4). High-field electron paramagnetic resonance spectroscopy reveals
the presence of an easy-plane anisotropy (D >
0)
with a significant transverse component, E, in compounds 1–3. These findings indicate that the
onset of one-dimensional spin correlations within the chain compound 4 leads to a suppression of quantum tunneling of the magnetization
within the easy plane, resulting in magnetic bistability and slow
relaxation behavior. Within this picture, it is the transverse E term associated with the ReIV centers that
determines the easy axis and the anisotropy energy scale associated
with the relaxation barrier. The results demonstrate for the first
time that slow magnetic relaxation can be achieved through optimization
of the transverse anisotropy associated with magnetic ions that possess
easy-plane anisotropy, thus providing a new direction in the design
of single-molecule and single-chain magnets.