在La替代的SmB6稀释不洁状态下的混合价值状态
M Zonno1,2,3,4, M Michiardi5,6,7, F Boschini6,8
1Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada. marta.zonno@synchrotron-soleil.fr.
Nature communications
|September 2, 2024
概括
在f电子系统中的混合价值 (MV) 行为在SmB6.6中被探索. 研究人员在SmxB6中观察到一种非常规的,重新进入的价值演变,挑战了对MV出现的现有理论.
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
- 稀土化学 稀土化学
背景情况:
- 在f电子系统中,混合价值 (MV) 行为,特别是萨马里六化物 (SmB6) 是一个复杂的现象.
- 了解MV出现的条件对于描述这些材料至关重要.
- SmB6 呈现出几乎退化的 Sm2+ 和 Sm3+ 配置,使其成为一个原型的 MV 系统.
研究的目的:
- 通过实验确定混合价值 (MV) 行为出现的局限性情况.
- 为了研究SmxB6系列中平均萨马价值 (vSm) 的演变.
- 挑战单调价值演变和整数值的趋同的预期.
主要方法:
- 使用角度分辨率光辐射光谱学 (ARPES) 来探测电子结构.
- 使用X射线吸收光谱法 (XAS) 确定平均萨马价值.
- 结合实验数据与现象学模型进行分析.
主要成果:
- 在La替换时观察到价值波动的线性减少,在x=0.2 (vSm ~ 2) 时接近抑制.
- 发现了令人惊的vSm随着x进一步下降而重新进入的增加,接近稀释物-不纯度极限 (vSm ~ 2.35).
- 证明了价值演变是非单调的,并且偏离了x → 0的预测.
结论:
- 这项研究揭示了SmxB6系列MV角色的非传统演变.
- 这些发现挑战了对MV出现及其对组成的依赖的基本理解.
- 结果促使进一步对稀土化合物中 MV 现象进行理论和实验研究.
相关概念视频
02:42Valence Bond Theory
8.5K
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...
8.5K
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
03:24Hybridization of Atomic Orbitals I
46.7K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
46.7K
02:54Trends in Lattice Energy: Ion Size and Charge
23.8K
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:
23.8K
03:26Electron Configuration of Multielectron Atoms
39.6K
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
39.6K
04:01VSEPR Theory and the Effect of Lone Pairs
41.9K
Effect of Lone Pairs of Electrons on Molecule Geometry
41.9K