来自原子尺度调制的巨大光学异构
Hongyan Mei1, Guodong Ren2, Boyang Zhao3
1Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Advanced materials (Deerfield Beach, Fla.)
|August 2, 2023
概括
研究人员发现了Sr9/8TiS3,这是一种具有创纪录的双折度 (Δn > 2.1) 的晶体,用于先进的光学应用. 这种材料具有非常高的折射率 (ne = 4.5) 和中到远红外光谱的低光损耗.
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
- 光学和光子学 在光学和光子学.
背景情况:
- 大双折射率 (Δn) 对于极化控制,非线性光学和新的光物相互作用至关重要.
- 多层2D材料具有高光学异构性,但受到外平面光学轴和弱层间合的限制.
- 现有的异性质材料在光学系统集成和可调性方面经常面临局限性.
研究的目的:
- 为了研究Sr9/8TiS3,一个具有周期性结构调制的散体晶体,其光学特性.
- 探索微妙的结构变化和显著的光学异构性之间的关系.
- 为先进的极化控制和可调节光学设备识别新材料.
主要方法:
- 大量晶体 Sr9/8TiS3.3 的合成和特征.
- 在中至远红外光谱中进行光学测量,以确定折射率 (ne,no).
- 结构分析以了解周期调制和过量的作用.
主要成果:
- Sr9/8TiS3是一种透明的,正无轴的晶体,异常指数ne=4.5和普通指数no=2.4.
- 创纪录的双断率 (Δn > 2.1) 实现了低光学损失.
- 过多的会导致TiS6的三角形 prismatic 单元,通过定向电子云来提升ne.
结论:
- 在Sr9/8TiS3中微妙的结构调制直接与折射率和双折射率的大变化有关.
- 这一发现为新类别的异构光学材料开辟了道路.
- 该材料显示了可调节光学设备的潜力,具有显著的折射率调制.
相关概念视频
Atomic Nuclei: Larmor Precession Frequency
1.5K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
1.5K
Atomic Emission Spectroscopy: Interference
229
In atomic emission spectroscopy (AES), high-temperature atomizers excite a broad range of elements and molecules that generate complex emissions from sources such as oxides, hydroxides, and flame combustion products in the flame or plasma. Several strategies can be employed to minimize spectral interferences caused by overlapping emission lines or bands. These include increasing instrument resolution, choosing alternative emission lines, optimally placing the detector in low-background regions,...
229
Atomic Force Microscopy
3.4K
Atomic force microscopy (AFM) is a type of scanning probe microscopy that can analyze topographic details of various specimens like ceramics, glass, polymers, and biological samples. AFM offers over 1000 times more resolution than the optical imaging system. Images generated from AFM are three-dimensional surface profiles, offering an advantage over the flat, two-dimensional images from other imaging techniques.
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
3.4K
Atomic Nuclei: Nuclear Magnetic Moment
1.2K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.2K
Atomic Absorption Spectroscopy: Interference
833
Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference.
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
833
Atomic Nuclei: Magnetic Resonance
685
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
685


