在压力下立方FeGe的磁力和格子动态之间的相关性
R-A Tonacatl-Monez1, R Heid2, O De la Peña-Seaman1
1Instituto de Física 'Ing. Luis Rivera Terrazas', Benemérita Universidad Autónoma de Puebla, Av. San Claudio & Blvd. 18 Sur, Ciudad Universitaria, C.P. 72570 Puebla, Puebla, Mexico.
概括
这项关于铁磁FeGe的研究揭示了施加的压力如何影响其磁性和动态性质. 研究人员使用了一种新的旋转缩放方法,发现压力减少了与电子 - 声子相互作用和磁矩变化相关的声子异常.
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
- 计算物理 计算物理
背景情况:
- 铁磁 (FM) 立方体B20 FeGe在压力下表现出复杂的行为.
- 标准密度函数理论 (DFT) 的计算经常难以准确预测其属性,特别是声异常.
- 了解压力诱导的磁力和晶格动态的变化对于材料应用至关重要.
研究的目的:
- 研究施加压力对FM立方B20FeGe的结构性,电子性,格子动态性和电子-声声合的作用.
- 使用旋转缩放交换相关性 (ssxc) 方法来完善理论预测,将临界压力与实验值对齐.
- 为了阐明在压力下磁矩和声子线宽之间的相关性.
主要方法:
- 雇佣的第一原则计算.
- 使用旋转缩放交换相关性 (ssxc) 方法来调整磁矩和相位能量.
- 分析了声子分散,电子-声子相互作用和电子关节密度的状态.
主要成果:
- ssxc方法成功调整了临界压力 (pc) 并使磁矩更接近实验值.
- 声波软化和R点附近的大线宽被ssxc减轻,并且随着压力增加而显著减少.
- 发声器异常和线宽的压力依赖性被发现与磁矩的行为并行,由电子-发声器矩阵元素驱动.
结论:
- 施加的压力显著影响FeGe的电子和晶格动态,减少声异常.
- ssxc方法为研究磁性材料中的压力效应提供了更准确的理论框架.
- 在FeGe的压力下,磁矩和声子线宽之间的相关性主要由电子声子矩阵元素控制,与其他B20材料不同.
相关概念视频
01:31Ferromagnetism
3.0K
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...
3.0K
02:54Trends in Lattice Energy: Ion Size and Charge
26.5K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
26.5K
03:02Colors and Magnetism
13.9K
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...
13.9K
02:42Valence Bond Theory
11.2K
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...
11.2K
01:18Magnetic Force
1.8K
In addition to the electric forces between electric charges, moving electric charges exert magnetic forces on each other. A magnetic field is created by a moving charge or a group of moving charges known as the electric current. A magnetic force is experienced by a second current or moving charge in response to this magnetic field. Fundamentally, interactions between moving electrons in the atoms of two bodies produce magnetic forces between them.
The magnetic force acting on a moving charge...
The magnetic force acting on a moving charge...
1.8K
02:58Crystal Field Theory - Octahedral Complexes
30.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.6K