在SNS单晶体中研究温度依赖的声不和和和热传输
Jue Li1,2, Ting Yan1,2, Xiangnan Gong1
1Analytical and Testing Center, Chongqing University, Chongqing 401331, P. R. China.
The journal of physical chemistry letters
|August 10, 2023
概括
硫化 (SnS) 具有出色的热电性能. 这项研究揭示了强烈的格子不协调性,由不对称的结合驱动,是SnS的关键.
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:
- 硫化 (SnS) 是一种IV-VI层的化合物,在b轴上具有显著的热电特性.
- 了解其热传输机制对于热电应用至关重要.
研究的目的:
- 通过使用温度依赖拉曼光谱法 (TDRS) 来量化SnS晶体中的声子无和性.
- 阐明导致SnS低导热率的潜在机制.
主要方法:
- 取决于温度的拉曼光谱 (TDRS) 从77K到475K.
- 分析包括三声波和四声波过程和格子热膨胀.
- 密度函数理论 (DFT) 对原子热位移和电荷密度的计算.
主要成果:
- 三声过程在研究温度范围内主导了SnS中的声散射.
- 计算的晶格导热率与实验数据有很好的一致性.
- 强烈的格子无和性,归因于来自Sn 5s2单双电子的不对称化学键,导致低导热.
结论:
- 声波无和性是限制SnS导热性的主要因素.
- 由于单双电子的不对称结合,大大导致了这种不和性.
- 这些发现提供了对低维材料热性质的洞察.
相关概念视频
Atomic Spectroscopy: Effects of Temperature
366
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature...
366
Thermal Sigmatropic Reactions: Overview
2.1K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.1K
Thermal Strain
1.6K
Thermal strain is a concept that arises when we consider how temperature changes affect structures. Unlike the conventional assumption that structures remain constant under load, real-world scenarios often involve temperature fluctuations that can significantly impact these structures. Consider a homogeneous rod with a uniform cross-section resting freely on a flat horizontal surface. If the rod's temperature increases, the rod elongates. This elongation is proportional to the temperature...
1.6K
Atomic Nuclei: Nuclear Spin State Population Distribution
1.0K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
1.0K
Theory of Metallic Conduction
1.4K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.4K
Types of Semiconductors
657
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
657


