Ti1-Mnの磁気元素に富んだ合金における最高超伝導変換温度
Ying-Jie Zhang1, Yijie Zhu1, Qing Li1
1National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Journal of the American Chemical Society
|July 22, 2024
まとめ
タイタン-マンガン (Ti-Mn) 合金では,高圧で26Kまで超伝導性が強化され,マンガンのような磁性元素が常に超伝導性を阻害するという考えに異議を唱えた.
科学分野:
- 凝縮物質物理学
- 材料科学
- 超伝導性
背景:
- マンガン (Mn) で示される磁気モメントは,一般的に超伝導性に有害である.
- Mnのような磁性元素を含む材料で超伝導性を達成することは,典型的には困難です.
研究 の 目的:
- 高圧下でベータ相のTi-Mn合金における超伝導性を調査する.
- 超伝導性に対する磁気モメントの影響を調査する.
- 超伝導体の磁気汚染の 常識的な理解に挑戦する
主な方法:
- ベータ相のTi-Mn合金に対する高圧実験.
- 構造分析のためのシンクロトロンX線微分
- 実験的発見を裏付ける最初の原理の計算.
主要な成果:
- Ti-Mn合金で約26Kの超伝導的移行温度 (Tc) を記録した.
- マンガンの含有量が大きいにもかかわらず,超伝導性の強化が観察されました.
- 上部臨界磁場は中圧状態でパウリーの限界を超えた.
- ベータ・フェーズ構造は,圧力下での連続した細胞体積収縮で安定したままでした.
結論:
- この研究は,Mnを含む合金における超伝導性の強化を示し,確立された理論と矛盾しています.
- 高圧は磁気材料の 超伝導性を促進します
- 観測されたTcの圧力依存性を完全に説明するには,さらなる理論的調査が必要である.
関連する概念動画
Superconductor
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
Types Of Superconductors
964
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...
964
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
Bonding in Metals
47.1K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
47.1K
Paramagnetism
2.5K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.5K
Atomic Nuclei: Nuclear Spin State Population Distribution
971
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.
971


