相关实验视频
Updated: Mar 26, 2026

06:53
Scanning SQUID Study of Vortex Manipulation by Local Contact
Published on: February 1, 2017
7.4K
在氧化物超级网中观测极旋
A K Yadav1,2, C T Nelson1,3,4, S L Hsu1,3,4
1Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
Nature
|January 28, 2016
概括
研究人员创建了新的电极化模式, 这些复杂的旋-反旋阵列为铁性材料的异常状态提供了新的途径.
科学领域:
- 凝聚物质物理学
- 材料科学
- 纳米技术
背景情况:
- 复杂的旋转拓是由电子带结构和旋转轨道合产生的.
- 铁质材料由于自旋,电荷,轨道和格子自由度的相互作用而表现出异国情调.
研究的目的:
- 在超级网格中设计复杂的电极化拓.
- 研究纳米尺度-抗阵列的形成和稳定性.
主要方法:
- 使用交替的酸和酸层制造超级网格.
- 通过扫描传输电子显微镜对极性原子位移进行原子尺度映射.
- 用相场建模来确定低能量状态和能量贡献.
主要成果:
- 观测近连续极化旋转的长距离有序-反阵列.
- 证实阵列代表特定超级网格时期的低能量状态.
- 在梯度,静电和弹性贡献之间确定能量平衡.
结论:
- 发明的电极化阵列模仿了自旋拓,为新的铁态开辟了道路.
- 创造新的物质状态的潜力, 比如双极天体和刺状态.
- 在材料中开发电气可控制的性.
相关概念视频
Potential Due to a Polarized Object
903
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
903
Dielectric Polarization in a Capacitor
6.5K
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
6.5K
Ferromagnetism
3.5K
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...
3.5K
Crystal Field Theory - Octahedral Complexes
31.7K
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...
31.7K
Electrostatic Boundary Conditions in Dielectrics
2.1K
When an electric field passes from one homogeneous medium to another, crossing the boundary between the two mediums imparts a discontinuity in the electric field. This results in electrostatic boundary conditions that depend on the type of mediums the field propagates through.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity....
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity....
2.1K
Trends in Lattice Energy: Ion Size and Charge
27.2K
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:
27.2K

