在二维过渡金属二二甲基化物中,扭转辅助的内在硬化
Xiaodong Zheng1,2, Shizhe Feng3, Chi Shing Tsang1,4
1Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Nature materials
|April 1, 2025
概括
研究人员发现,扭曲二维材料可以提高其性,而不会损害强度. 这种新的方法允许连续发生断裂事件,改善先进应用的材料弹性.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 纳米技术 纳米技术
背景情况:
- 材料断裂通常是不可逆转的,限制了部件的寿命.
- 散装材料已被设计为强度和性,但低维材料往往保持脆性.
- 在不牺牲强度的情况下提高断裂性是材料工程中的一个关键挑战.
研究的目的:
- 研究一种新的方法来提高二维 (2D) 材料的断裂性.
- 探索扭曲的2D材料结构中强度增强背后的机制.
- 为了确定是否可以保持强度,同时提高2D材料的性.
主要方法:
- 在现场扫描传输电子显微镜 (STEM) 观察骨折事件.
- 纳米印记用于测量机械性能.
- 理论分析以了解底层的硬化机制.
主要成果:
- 扭曲的双层二维材料表现出连续的断裂事件,在最初的裂中愈合成稳定的粒度边界.
- 这些谷物边界有效地屏蔽了随后的裂纹尖端,防止了灾难性的故障.
- 强度增强可通过调整层间的扭曲角度来调整.
- 这个过程比传统的骨折消耗更多的能量,这表明性增加.
结论:
- 扭曲2D材料提供了一种内在的机制,可以在不牺牲强度的情况下增强断裂性.
- 观察到的连续断裂和裂屏蔽为设计弹性二维材料提供了新的途径.
- 这一发现,结合twistronics的电子特性,为先进的设备应用开辟了道路.
相关概念视频
Metallic Solids
18.1K
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...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and...
18.1K
Properties of Transition Metals
24.6K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
24.6K
Crystal Field Theory - Tetrahedral and Square Planar Complexes
40.9K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
40.9K
Crystal Field Theory - Octahedral Complexes
25.8K
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...
25.8K
Yield Criteria for Ductile Materials under Plane Stress
127
In designing structural elements and machine parts using ductile materials, it is crucial to ensure that these components withstand applied stresses without yielding. Yielding is initially determined through a tensile test, which evaluates the material's response to uniaxial stress. However, tensile stress is insufficient when components face biaxial or plane stress conditions This condition requires advanced criteria to predict failure.
The Maximum Shearing Stress Criterion, also known as...
The Maximum Shearing Stress Criterion, also known as...
127


