磁性特性和Ln = Dy的磁热效应,Tb是基于碳酸的金属有机框架
Zhen Li1,2, Ana Arauzo3, José Giner Planas1
1Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain. ebartolome@icmab.es.
Dalton transactions (Cambridge, England : 2003)
|April 23, 2024
概括
我们合成了基于碳酸的新兰化物金属有机框架 (MOFs),表现出Ising旋转行为. 这些材料显示了磁性冷却应用的潜力,Dy和Tb MOF 显示了接近 1.6 K 的显著磁热效应.
科学领域:
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
- 化学 化学 化学
背景情况:
- 兰化物金属有机框架 (MOF) 由于其可调节的结构和磁性特性,对磁性应用具有前景.
- 基于carborane的链接器为MOF设计提供了独特的结构和电子特性.
- 了解以兰坦化为基础的MOF的磁性行为和磁热效应 (MCE) 对于开发先进的磁性材料至关重要.
研究的目的:
- 用Dy和Tb.合成和表征基于碳酸的新型兰坦化MOFs.
- 研究磁热特性,包括磁相互作用和放松动态.
- 为了评估潜在的冷冷却应用的磁热效应.
主要方法:
- 基于碳酸的兰坦化MOF的合成,其配方是 {[(Ln) 3(mCB-L) 4(NO3) ((DMF) ]·溶液} (Ln = Dy, Tb).
- 使用 dc 和 ac 易感性,X射线吸收光谱学 (XAS),X射线磁圆二元化 (XMCD) 和热容量测量进行表征.
- 分析磁体结构,旋转动力学和磁热效应.
主要成果:
- MOFs形成1D聚合物链的兰坦化离子与链和链之间的反铁磁合的弱铁磁相互作用.
- Dy MOF表现出缓慢的磁化放松,包括热激活过程和磁化的量子道化.
- 观察到最大的磁变化为5.71 J kg-1 K-1 (Dy) 和4.78 J kg-1 K-1 (Tb),MCE峰值在1.6 K左右.
结论:
- 碳基兰坦化物MOF表现出复杂的磁性行为,包括Ising旋转特征和缓慢的磁性放松.
- 这些材料具有显著的磁热效应,使它们成为低温磁性制冷的有希望的候选者.
- 这项研究强调了将碳联结剂纳入兰坦化MOF中的潜力,以获得先进的磁性功能.
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