Superconductivity Examples

Mercury Superconducting Transition

水银超导转变

H. K. Onnes, Commun. Phys. Lab.12,120, (1911)

H. K. Onnes, Commun. Phys. Lab.12,120, (1911)（专名或术语）

Mercury was historically the first to show superconductivity, and it is an example of a Type I superconductor. Its practical usefulness is limited by the fact that its critical magnetic field is only 0.019 T, so the amount of electric current it can carry is also limited.

Show phase diagram

显示相图

汞是历史上第一个显示出超导性的材料，它是一个Type I超导体的例子。其实际应用受到限制，因为它的临界磁场仅为0.019 T，因此它能承载的电流量也受到限制。

Niobium-Tin Superconductor

铌-锡超导体

B. T. Matthias, et al., Phys. Rev. 95, 1435, (1954)

B. T. Matthias 等，Phys. Rev. 95, 1435, (1954)

The superconducting transition of niobium-tin was observed by measuring the inductance of a coil which was wrapped around the sample. At the superconducting transition, the magnetic field is expelled by the Meissner effect and the inductance drops.

铌锡的超导相变是通过测量绕样品缠绕的线圈的电感来观察的。在超导相变时，磁场被迈斯纳效应排斥，电感下降。

This measurement was made by immersing the coil in liquid hydrogen and measuring the inductance as a function of temperature.

这项测量是将线圈浸入液态氢中，并测量温度作为函数的电感。

Further discussion

进一步讨论

Lanthanum-Barium-Copper Oxide Superconductor

Lanthanum-Barium-Copper Oxide Superconductor（专名或术语）

Bednorz and Muller, Z. Physik B64, 189, (1986)

贝德诺兹和穆勒，Z. Physik B64, 189, (1986)

This ceramic material was the first of a new class of high temperature superconductors. It is made by randomly substituting some barium atoms into the lattice of lanthanum- copper-oxide in what is termed a solid solution.

More detail

更多内容

这种陶瓷材料是新型高温超导体中的第一种。它通过将一些钡原子随机地掺入 lanthanum-copper-oxide 的晶格中来制备，这种过程被称为固溶体。

Yttrium-Barium-Copper Oxide

钇-钡-铜氧化物

high temperature superconductors

liquid nitrogen

M. K. Wu, et al., Phys. Rev. 58, 908 (1987)

M. K. Wu, et al., Phys. Rev. 58, 908 (1987)（专名或术语）

Structure and discussion

结构与讨论

Magnetic levitation

磁悬浮

Power applications

功率应用

This disc of YBaCuO certainly doesn't look or feel like an electrical conductor. It is a hard, brittle ceramic material. It looks like something you would make a grinding wheel out of - the fact that it can become a perfect conductor is hard to believe.

这个YBaCuO盘显然看起来和感觉上都不像一个电导体。它是一种坚硬而易碎的陶瓷材料。它看起来像是用来制作磨轮的材料——它能够成为完美导体的事实很难让人相信。

But when a small rare-earth magnet is placed on it and liquid nitrogen is poured around it, the magnet levitates, showing the Meissner effect characteristic of the zero-resistance state. In the illustration, the black YBaCuO disc is held in a brass mount to facilitate cooling and holding it at liquid nitrogen temperature.

但当一个小型的稀土磁体放在上面，并将液氮倒入周围时，磁体会悬浮起来，显示出零电阻状态的迈斯纳效应。在示意图中，黑色的YBaCuO盘被固定在黄铜支架上，以便冷却和保持在液氮温度下。

这种陶瓷材料是首批在高于液氮温度（77 K）发生相变的高温超导体之一。