(H₂mela)₂[FeCl₅]Cl (mela = melamine): A Cl-bridged single-chain magnet based on weak ferromagnetism

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• 作者：Dan-Feng Weng ; Bing-Wu Wang ; Zhe-Ming Wang ; Song Gao
• 关键词：Cl-bridged chain compounds ; Weak ferromagnetism ; Spin canting ; Single-chain magnet ; Finite size effects
• 刊名：Coordination Chemistry Reviews
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：257
• 期：17-18
• 页码：2484-2490
• 全文大小：1235 K

文摘

Presented here are the structures and magnetism of two isostructural magnetic Cl-bridged chain compounds of the type (H₂mela)₂[MCl₅]Cl (melamelamine, MFe(II) (class=""boldFont"">1), MMn(II) (class=""boldFont"">2)). The chain structure is formed along the Jahn-Teller elongation axis of the MCl₆ octahedra. In compound class=""boldFont"">1, the Cl^? ion transmits an antiferromagnetic exchange interaction that, combined with the magnetic anisotropy of the Fe(II) sites, gives rise to a canted antiferromagnetic arrangement of the spins. Detailed magnetic studies revealed that class=""boldFont"">1 exhibits slow magnetic relaxation behavior like single-chain magnet (SCM), and that the finite size effects, due to naturally occurring defects, strongly influences the static and dynamic properties of class=""boldFont"">1. The contribution of the correlation length to the energy barrier has also been investigated.

The Mn compound class=""boldFont"">2 is an isotropic Heisenberg chain with antiferromagnetic coupling between the Mn(II) ions. Doped crystals of class=""boldFont"">Zn1, class=""boldFont"">Cu1-class=""boldFont"">Cu5 and class=""boldFont"">Mn1-class=""boldFont"">Mn5 were synthesized by introducing different contents of Zn(II), Cu(II) and Mn(II) ions to study the magnetic dilution and decoupling phenomena, respectively.