在maghemite基纳米混合体中,协调复合体和纳米颗粒之间的室温持久磁相互作用
Leonardo Curti1, Yoann Prado2, Aude Michel2
1Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005, Paris, France. laurent.lisnard@sorbonne-universite.fr.
Nanoscale
|May 17, 2024
概括
磁石纳米颗粒与复合物的表面功能化显著提高了磁性异性质. 这种分子效应通过氧介导交换相互作用增强磁性,即使在室温下.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 磁力学 磁力学 是一种
背景情况:
- 磁石纳米颗粒具有内在的磁性特性.
- 表面功能化是调整纳米粒子行为的一个关键策略.
- 协调复合体为修改材料性质提供了多功能平台.
研究的目的:
- 为了研究Co(II) 协调复合体对maghemite纳米粒子磁性异性质的影响.
- 阐明负责磁性性能增强的潜在机制.
- 探索观察到的磁效应的温度依赖性.
主要方法:
- 磁石石纳米颗粒的表面功能化与Co (II) 协调复合体.
- 磁力测量研究,以评估磁性特性,如阻塞温度和强制场.
- X射线吸收光谱 (XAS) 和X射线磁圆二元化 (XMCD) 用于探测原子和电子结构.
- 计算模拟以确定交换场值.
主要成果:
- Co(II) 功能化导致磁性异构显著增加,阻塞温度翻倍,强迫场增加六倍.
- 磁力测量和光谱学显示,这种效应源于分子相互作用和界面交换,而不是表面障碍.
- 磁性异构增强延伸到纳米粒子核心,由异构交换驱动.
- 强烈的磁交互相互作用被证实,持续到室温.
- 在室温下,Ni(II) 类似物也表现出基质诱导的磁反应.
结论:
- 用协调复合体进行表面功能化是增强纳米粒子磁性异质性的有效策略.
- 氧化物协调桥梁在介导复杂物和纳米粒子之间的强磁交换相互作用方面发挥着至关重要的作用.
- 观察到的效应是分子起源和坚固的,在室温下持久,在先进的磁性材料中具有潜在的应用.
更多相关视频
09:01Magnetic-, Acoustic-, and Optical-Triple-Responsive Microbubbles for Magnetic Hyperthermia and Pothotothermal Combination Cancer Therapy
Published on: May 22, 2020
3.1K
08:13Using Magnetometry to Monitor Cellular Incorporation and Subsequent Biodegradation of Chemically Synthetized Iron Oxide Nanoparticles
Published on: February 27, 2021
4.6K
相关概念视频
01:31Ferromagnetism
2.4K
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...
2.4K
03:02Colors and Magnetism
11.6K
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...
11.6K