在压力下铁的非磁性状态下的超导性
K Shimizu1, T Kimura, S Furomoto
1Department of Physical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan. kshimizu@mp.es.osaka-u.ac.jp
Nature
|July 19, 2001
概括
铁在受到高压 (1530 GPa) 的情况下,在低温 (低于2 K) 时变得超导. 这发生在铁中.
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
背景情况:
- 铁磁性和超导性通常是传统超导体中的竞争现象.
- 金属可以在低温下在其非磁性状态中表现出超导性.
- 铁在10 GPa以上的压力下转化为非磁性结构,在这个阶段预测超导性.
研究的目的:
- 为了研究高压下非磁铁的超导性潜力.
- 实验证实铁在高压下预测的超导特性.
主要方法:
- 铁的高压合成和表征.
- 测量电阻力作为温度和压力的函数.
- 检测梅斯纳效应以确认超导.
主要成果:
- 在低于2K的温度下,铁表现出超导性.
- 铁在15至30GPa的压力下观察到超导性.
- 电阻的明显下降和梅斯纳效应证实了超导过渡.
结论:
- 高压诱导的非磁铁可以成为超导体.
- 这些发现挑战了对超导相竞争相的传统理解.
- 在压力下铁的超导行为为材料科学研究开辟了新的途径.
更多相关视频
相关概念视频
01:27Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:22Magnetic Force On Current-Carrying Wires: Example
In a magnetic field, moving charges encounter a force. If a wire contains these moving charges, i.e., if the wire is carrying a current, then a force acts on the wire as well. Consider a pair of flexible leads holding a wire that is 40 cm long and 10 g in weight in a horizontal position. The wire is placed in a constant magnetic field of 0.40 T, as shown in Figure 1(a). Determine the magnitude and direction of the current flowing in the wire needed to remove the tension in the supporting leads.
01:24Superconductor
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...
01:28Types Of Superconductors
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...
01:31Ferromagnetism
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...
01:18Magnetic Force
In addition to the electric forces between electric charges, moving electric charges exert magnetic forces on each other. A magnetic field is created by a moving charge or a group of moving charges known as the electric current. A magnetic force is experienced by a second current or moving charge in response to this magnetic field. Fundamentally, interactions between moving electrons in the atoms of two bodies produce magnetic forces between them.
The magnetic force acting on a moving charge...
The magnetic force acting on a moving charge...