低温铁磁顺序在一个双层层的2+材料中
Patrick W Doheny1, Gavin B G Stenning2, Adam Brookfield3
1School of Chemistry and Forensic Science, Ingram Building, University of Kent, Canterbury CT2 7NH, U.K.
概括
这项研究揭示了二维材料CoHydCl的磁性行为. 铁磁相互作用在低温出现,导致在246mK以下的长距离有序状态.
科学领域:
- 固态物理 固态物理
- 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:
- 研究二维层材料的磁性对于开发新型电子设备至关重要.
- 高旋转的CO2+复合体具有独特的磁性特性.
研究的目的:
- 为了全面描述[Co(NH3NH2) 2(H2O) 2Cl2]Cl2 (CoHydCl) 的磁性特性.
- 了解低温下CoHydCl中的自旋状态转换和磁相互作用.
主要方法:
- 电子偏磁共振 (EPR) 光谱学
- 测量磁性易感度的测量方法
- 低温热容量测量 低温热容量测量
- 通过中子衍射进行了反射.
主要成果:
- EPR研究表明,在50K以下的中,从J=3/2转向J=1/2的旋转状态发生过渡.
- 配备了两级模型的磁性易感性数据表明,相互作用比以前假设的要弱.
- 铁磁相互作用在2K附近变得显著,在246mK以下出现了远程有序状态,通过中子衍射证实是铁磁的.
结论:
- CoHydCl 的磁性属性由自旋状态转换和低温铁磁相互作用主导.
- 在246mK以下建立了远程铁磁有序状态.
- 中子衍射证实了低温有序状态的铁磁性质.
相关概念视频
Ferromagnetism
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
Fermi Level
539
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
539
Colors 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
Metallic Solids
18.3K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.3K
Types Of Superconductors
954
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...
954
Fermi Level Dynamics
228
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
228


