The Canted Antiferromagnetic Approach to Single-Chain Magnets
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- 作者：Kevin Bernot ; Javier Luzon ; Roberta Sessoli ; Alessandro Vindigni ; Julien Thion ; Sé ; bastien Richeter ; Dominique Leclercq ; Joulia Larionova ; Arie van der Lee
- 刊名：Journal of the American Chemical Society
- 出版年：2008
- 出版时间：February 6, 2008
- 年：2008
- 卷：130
- 期：5
- 页码：1619 - 1627
- 全文大小：391K
- 年卷期：v.130,no.5(February 6, 2008)
- ISSN：1520-5126
文摘
The reaction of manganese(III) acetate meso-tetraphenylporphyrin with phenylphosphinic acidprovides the one-dimensional compound of formula [Mn(TPP)O2PHPh]·H2O, which crystallizes in themonoclinic C2/c space group. The chain structure is generated by a glide plane resulting in Jahn-Tellerelongation axes of the MnIII octahedra that alternate along the chain. The phenylphosphinate anion transmitsa sizable antiferromagnetic exchange interaction that, combined with the easy axis magnetic anisotropy ofthe MnIII sites, gives rise to a canted antiferromagnetic arrangement of the spins. The static single-crystalmagnetic properties have been analyzed with a classical Monte Carlo approach, and the best fit parametersfor the exchange and single ion anisotropy are J = -0.68(4) K and D = -4.7(2) K, respectively (using the-2JSiSj formalism for the exchange). Below 5 K the single-crystal dynamics susceptibility reveals afrequency-dependent out-of-phase signal typical of single-chain magnets. The extracted relaxation timefollows the Arrhenius law with 
= 36.8 K. The dynamic behavior has been rationalized and correlated togeometrical parameters of the structure. The contribution of the correlation length to the energy barrierhas been investigated, and it has been found that the characteristic length that dominates the dynamicsstrongly exceeds the correlation length estimated from magnetic susceptibility.
= 36.8 K. The dynamic behavior has been rationalized and correlated togeometrical parameters of the structure. The contribution of the correlation length to the energy barrierhas been investigated, and it has been found that the characteristic length that dominates the dynamicsstrongly exceeds the correlation length estimated from magnetic susceptibility.