What is the maximum temperature that can be reached by superconductors at present

On October 10, 2009, American scientists synthesized the substance.

TL4BA)Ba2Ca2Cu7O13+, raising the superconducting temperature to 254K, only 19 from freezing. It seems that there are no superconductors above 0 yet.

125k, we learned it in physics class!

In 1973, the discovery of a superconducting alloy, the niobium-germanium alloy, had a critical superconducting temperature equivalent to that of Niobium-Germanium, a record that stood for 13 years. In 1986, the research center of IBM Corporation in the United States, located in Zurich, Switzerland, reported that an oxide has a high-temperature superconductivity of 35K, which caused a sensation in the world scientific community. Since then, scientists have been racing against the clock to tackle key problems, and almost every few days, new research results appear.

In just over a year from 1986 to 1987, the critical superconducting temperature increased by more than 100K, which is a miracle in the history of material development and even the history of scientific and technological development. The continuous advent of high-temperature superconducting materials has paved the way for superconducting materials to move from the laboratory to application.

The temperature of high-temperature superconductivity is -70°C.

In 2015, physicists discovered that hydrogen sulfide undergoes superconducting phase transitions at a temperature of about 203 K (-70 °C) at extremely high pressure (at least 150 GPA, that is, about 1.5 million standard atmospheres), making it the hottest superconductor known at present.

High-temperature superconductors are a group of superconducting materials with general structural characteristics and relatively moderately spaced copper oxide planes. They are also known as copper oxide superconductors. In some of the compound-scale rocks in this group, the critical temperature at which superconductivity occurs is the highest among known superconductors.

Mechanism of high-temperature superconductivity

Electron pairing mechanism of high-temperature superconductors. The consensus view is that due to the strong electronic correlation of the carriers, the ground state of the undoped copper oxide is an antiferromagnetic Mott insulator, and there is a Cu2+-Cu2+ ion nearest neighbor antiferromagnetic (AFM) exchange in the CuO2 plane, and the temperature of the Nair decreases after doping until the long-range antiferromagnetic order disappears, resulting in superconductivity, but the superconducting state still maintains the spin correlation of short-range AFM.

Experiments have confirmed that the low-energy spin excitation of p-type and n-type high-temperature oxide superconductors is different, the p-type oxide is a non-common spin-excited clump oak with permeable accessory gaps, while the low-energy spin excitation in n-type oxide is the spin density wave SDW.

The above content refers to Encyclopedia - High Temperature Superconductivity.

Copper oxide, breaking through the liquid nitrogen temperature region (77K).

There are YBCO-92K, BSCco-110K, TBCCO-138K, etc.

Professor Zhu Jingwu has reported a superconductor with a transition temperature of 164 K at high pressure.

High-temperature superconducting materials are not only based on the critical temperature, but also on their processing performance, that is, whether they can be drawn into wires or processed into a certain shape, so that they have practical value.

At present, the first generation of high-temperature superconducting materials in the world is bismuth-based superconductors, and the second generation is yttrium-barium-copper-oxygen, called yttrium-based superconductors (YBCO), with a critical temperature of 90K (183), and later bismuth-strontium-calcium copper-oxygen superconductors (BSCCO) were discovered, with a critical temperature of 110K (163). Later, the discovery of titanium barium calcium copper oxygen (TBCCO) 138K (-135) with this superconductor has been made of superconducting cables, superconducting magnets, superconducting transformers, superconducting motors, etc., the test of superconducting cables has reached the stage of grid-connected tests, China is not lagging behind in this regard, but superconducting wires have to be imported. Japan is relatively advanced in this regard.