基桥 {Fe2Co} 组件显示了超磁性过渡和磁热效应
Yu-Jing Gao1, Ji-Peng Luo2, Nan Yin2
1State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024, P. R. China. mengys@dlut.edu.cn.
Dalton transactions (Cambridge, England : 2003)
|July 14, 2025
概括
两个新的分子磁铁,普鲁士蓝色类似物 (PBAs),表现出场诱导的磁过渡. 化合物1显示可调节的磁性合和显著的磁热效应,推进分子磁力.
科学领域:
- 分子磁力学分子磁力学
- 材料科学是一种材料科学.
- 跨学科的物理和化学.
背景情况:
- 材料中非常规的磁拓是先进应用的关键.
- 普鲁士蓝色类似物 (PBA) 是具有可调节性质的多功能分子磁铁.
- 金属中心和连接体的合理设计可以控制磁相互作用.
研究的目的:
- 报告两种基于三二酸盐桥的异金属分子磁铁.
- 研究磁场诱导的磁相转换和磁结构相关性.
- 探索旋转电子和磁热冷却的潜在应用.
主要方法:
- 合成异金属分子磁铁[PzTp]Fe[CN]3]2[Co[DypU]·H2O (1) 和 (Tp*) [Fe[CN]3]2[Co[DypU]·H2O (2) 的合成.
- 使用X射线衍射来确定网络拓的结构性表征.
- 测量磁性易感性 (可变温度和可变场) 以分析磁性合和相位过渡.
主要成果:
- 化合物1和2形成1D双链,连接成2D网络.
- 化合物1显示铁磁合;化合物2显示反铁磁合.
- 复合物1显示了场诱导的从旋转向AFM到对线AFM (3.5kOe) 的过渡,然后接近FM (18kOe),具有磁热效应 (ΔS = 23.22 J K-1 kg-1).
结论:
- 辅助连接物调制对于调整分子磁铁中的磁相互作用和拓学是有效的.
- 了解磁结构相关性对于设计新型磁性材料至关重要.
- 这些PBA显示了先进磁性应用的潜力,包括磁热冷却.
相关概念视频
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K
03:02Colors and Magnetism
12.3K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.3K
01:26Diamagnetism
2.5K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.5K
01:30Paramagnetism
2.6K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.6K
01:28Types Of Superconductors
1.1K
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
1.1K
02:42Valence Bond Theory
9.2K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
9.2K