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A superconducting magnet is an electromagnet ... is to build magnets that can be cooled by liquid nitrogen alone. At temperatures above about 20 K cooling can be ...
High-temperature superconductivity (high-T c or HTS) is superconductivity in materials with a critical temperature (the temperature below which the material behaves as a superconductor) above 77 K (−196.2 °C; −321.1 °F), the boiling point of liquid nitrogen. [1]
In the class of superconductors known as type II superconductors, including all known high-temperature superconductors, an extremely low but non-zero resistivity appears at temperatures not too far below the nominal superconducting transition when an electric current is applied in conjunction with a strong magnetic field, which may be caused by ...
The table below shows some of the parameters of common superconductors.X:Y means material X doped with element Y, T C is the highest reported transition temperature in kelvins and H C is a critical magnetic field in tesla.
The temperature of liquid nitrogen can readily be reduced to its freezing point −210 °C (−346 °F; 63 K) by placing it in a vacuum chamber pumped by a vacuum pump. [2] Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of ...
Other type-II examples are the cuprate-perovskite ceramic materials which have achieved the highest superconducting critical temperatures. These include La 1.85 Ba 0.15 CuO 4, BSCCO, and YBCO (Yttrium-Barium-Copper-Oxide), which is famous as the first material to achieve superconductivity above the boiling point of liquid nitrogen (77 K).
The most famous ReBCO is yttrium barium copper oxide, YBa 2 Cu 3 O 7−x (or Y123), the first superconductor found with a critical temperature above the boiling point of liquid nitrogen. [10] Its molar ratio is 1 to 2 to 3 for yttrium, barium, and copper and it has a unit cell consisting of subunits, which is the typical structure of perovskites .
High-temperature superconductors (HTS) become superconducting at more easily obtainable liquid nitrogen temperatures, which is much more economical than liquid helium that is typically used in low-temperature superconductors. HTS are ceramics, and are fragile relative to conventional metal alloy superconductors such as niobium-titanium.