在哈夫尼亚的多次参数铁电域壁运动中核化机制
Songsong Zhou1, Andrew M Rappe1
1Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323.
概括
由于稳定的域壁,铁电氧化切换很困难. 控制域壁类型可以实现更快的切换和更低的强制场在铁电器件.
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
- 固态化学 固态化学
背景情况:
- 铁电氧化氧化物 (HfO2) 由于其强大的极化,对与相容的铁电设备有很大的希望.
- 然而,其实际应用受到困难的两极化切换的阻碍,基础机制尚不清楚.
研究的目的:
- 研究铁电哈夫尼亚的180度域壁及其在核化过程中的运动.
- 阐明挑战极化切换行为背后的原因.
主要方法:
- 理论研究域壁结构和对称性在多次参数铁电 hafnia.
- 对二极管模式和与不同域壁类型相关的域壁能量进行分析.
主要成果:
- 哈夫尼亚的多个顺序的参数域表现出复杂的3D双极模式,导致具有不同对称性的域壁.
- 一种常见的复杂域壁类型,涉及两极化和四边形反转,具有低能量,但在原子核上产生高能量带电壁,阻碍核和切换.
- 一种更简单的域壁类型,仅涉及极化反转,具有更高的能量,但形成扩散性,低能量的充电壁,促进更容易的核和运动.
结论:
- 复杂的域壁的稳定性解释了哈夫尼亚难以切换的极化.
- 域壁核化理论对于多序参数系统是先进的.
- 控制域壁种群提供了一种实现快速偏振切换和减少基于哈夫尼亚的铁电器件中的强制场的策略.
更多相关视频
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.0K
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.5K
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
Ionic Crystal Structures
14.1K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.1K
Metallic Solids
18.2K
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....
18.2K
Molecular Orbital Theory II
19.0K
Molecular Orbital Energy Diagrams
19.0K
Mechanism of Lamellipodia Formation
2.5K
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
2.5K
Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.4K
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 the dxy,...
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 the dxy,...
41.4K
