在一维的A3Hf2B3类型电极中预测的超导性.
Yulong Chen1, Teng Xie1, Ziqiang Chen1
1Multiscale Computational Materials Facility & Materials Genome Institute, School of Materials Science and Engineering, Fuzhou University Fuzhou 350108 P. R. China clwen@fzu.edu.cn bssa@fzu.edu.cn.
RSC advances
|November 29, 2023
概括
研究人员发现了新的超导无机电极,有可能在中等压力下应用. 这些材料,包括Sr3Hf2Pb3,显示出有希望的超导过渡温度,为材料科学提供了新的途径.
科学领域:
- 固态物理与材料科学 固态物理与材料科学
- 超导电性 超导电性 超导电性
- 计算材料设计设计 计算材料设计
背景情况:
- 由阴离子电子特征的无机电极是超导的候选物.
- 大多数已知的电极都需要高压才能达到显著的超导过渡温度 (Tc).
- 发现在低或中等压力下超导的电极是关键的研究目标.
研究的目的:
- 在A3Hf2B3材料类内计算选和识别新型超导电极.
- 研究潜在电极候选物的电子结构和声子特性.
- 为了预测有前途的材料的超导过渡温度 (Tc).
主要方法:
- 密度函数理论 (DFT) 的计算被用来构建和分析一系列A3Hf2B3化合物 (A = Mg,Ca,Sr,Ba;B = Si,Ge,Sn,Pb).
- 分析包括电子结构计算和声子分散谱,以确定稳定的一维电极.
- 进行了电子 - 声子合计算,以预测超导和过渡温度.
主要成果:
- 确定了稳定的一个维的电极Ca3Hf2Ge3,Ca3Hf2Sn3和Sr3Hf2Pb3.
- 预测这些电极具有超导性,其中Sr3Hf2Pb3的Tc最高为4.02K.
- Ca3Hf2Ge3和Ca3Hf2Sn3的预测Tcs分别为1.16K和1.04K. 施加20 GPa的压力使Ca3Hf2Ge3的Tc增加到1.96K,这是由于声变软.
结论:
- 这项研究扩大了已知的超导电极的库.
- 已识别的材料,特别是Sr3Hf2Pb3,是低压超导研究的有希望的候选材料.
- 这些发现为设计和合成新型电极和超导材料提供了重要的指导.
相关概念视频
01:24Superconductor
1.1K
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
1.1K
01:28Types Of Superconductors
993
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
993
01:31Ferromagnetism
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
03:02Colors and Magnetism
11.7K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.7K
01:17Theory of Metallic Conduction
1.3K
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,...
1.3K
02:37Metallic Solids
18.4K
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....
18.4K