通过非传统的协调几何学增强的离子异性质:单链磁铁行为,用于设计具有七度坐标Fe (II) 的[{Fe (II) L}2{Nb (IV) (CN) 8}]螺旋链化合物
Thengarai S Venkatakrishnan1, Shaon Sahoo, Nicolas Bréfuel
1CNRS, Laboratoire de Chimie de Coordination, 205, route de Narbonne, F-31077 Toulouse, France.
Journal of the American Chemical Society
|April 13, 2010
概括
一种新的1D异核铁-化合物表现出单链磁铁行为,这是由于高效的磁交换合和非传统的七度协调. 这种Fe (II) -Nb (IV) 材料具有显著的磁性特征,包括歇斯底里和磁性雪崩.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 单链磁铁 (SCM) 是具有缓慢磁性放松的分子材料.
- 开发具有增强磁性特性的新型SCM对于纳米技术应用至关重要.
- 基于铁的SCM已被广泛研究,但实现高效的磁交换合仍然是一个挑战.
研究的目的:
- 为了合成和表征一种新的1D异质核{Fe{II}Nb{IV}}化合物.
- 调查磁性特性并了解导致单链磁铁行为的因素.
- 探索非传统的协调和磁交换合在设计先进的磁性材料的潜力.
主要方法:
- 使用Fe (II) 和八甲酸盐[M (CN) (8)) ] (M = Nb (IV)) 合成蓝色桥梁异金属链.
- X射线衍射 (单晶和粉末) 用于1D聚合物结构的结构确定.
- 磁性易感性,高场EPR,磁化和莫斯尔光谱法用于描述磁性行为和自旋相互作用.
主要成果:
- 合成了一种具有七度协调和高效抗铁磁性 {Fe-Nb} 交换合 (J = -20 cm(-1)) 的1D异核 {Fe(II) Nb(IV) } 化合物.
- 该化合物表现出单链磁铁行为,具有缓慢的磁化放松 (Delta/k(B) = 74 K,tau(0) = 4.6 x 10(-11) 秒).
- 观察到的歇斯底里循环,4kOe强迫场和低温的磁性雪崩过程表明显著的磁性异构和高效的交换.
结论:
- 非传统的七度协调与高效的{Fe-Nb}磁交换合相结合,导致研究的1D化合物具有显著的磁性.
- 观察到的SCM行为,歇斯底里斯和磁雪崩归因于强烈的交换相互作用的相互作用和Fe (II) 单元的显著异构性.
- 这项研究突出了一个有前途的策略,用于设计具有调节性质的先进分子磁性材料.
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