在NiI中,令人惊的压力诱导的磁变化从磁体秩序转变为反铁磁状态
Qiye Liu1,2, Wenjie Su2, Yue Gu3
1College of Integrated Circuits and Optoelectronic Chips, Shenzhen Technology University, Shenzhen, 518118, China.
Nature communications
|May 6, 2025
概括
水静压调整了NiI2片中的磁相互作用,增加了过渡温度. 在7GPa时,可逆的磁到反铁磁 (AFM) 阶段过渡突出了层间磁合的关键作用.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 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:
- 范德瓦尔斯 (vdW) 磁铁表现出独特的磁性特性,受层间相互作用的影响.
- 施加压力是调整这些层间磁相互作用和磁顺序的强大工具.
- 了解压力诱导的磁相过渡对于新型设备应用至关重要.
研究的目的:
- 为了研究水静压对NiI2 vdW磁铁磁性特性的影响.
- 探索压力诱导的磁和反铁磁 (AFM) 状态之间的相位过渡.
- 阐明层间磁相互作用在确定NiI2.2的磁性基本状态中的作用.
主要方法:
- 在高达11 GPa的水静压下对NiI2片进行实验性研究.
- 对黑磁和反铁磁状态的磁过渡温度的分析.
- 蒙特卡洛模拟以模拟层间相互作用对磁性排序的影响.
主要成果:
- 观察到磁性过渡温度的显著增加,无论是磁极和AFM状态,压力都在增加.
- 发现了可逆的黑磁到AFM相位过渡在7GPa左右,挑战了现有的理论.
- 蒙特卡洛模拟证实了第二近邻邻层间相互作用在有利于AFM状态而不是层内挫折的关键作用.
结论:
- 层间的磁相互作用对于决定像NiI2.2这样的vdW磁铁的磁性基态至关重要.
- 观察到的压力诱导相位过渡为磁性排序机制提供了新的见解.
- 这些发现为通过控制层间合来设计先进的纳米磁器件提供了机会.
相关概念视频
01:31Ferromagnetism
2.3K
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...
2.3K
01:30Paramagnetism
2.5K
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...
2.5K
01:26Diamagnetism
2.4K
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....
2.4K
01:31Magnetic Susceptibility and Permeability
861
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
861
03:02Colors and Magnetism
11.3K
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...
11.3K
01:23Atomic Nuclei: Nuclear Relaxation Processes
581
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
581