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Superconductors may be considered perfect diamagnets, and completely expel magnetic fields due to the Meissner effect when the superconductivity initially forms; thus superconducting levitation can be considered a particular instance of diamagnetic levitation. In a type-II superconductor, the levitation of the magnet is further stabilized due ...
The experiment demonstrated for the first time that superconductors were more than just perfect conductors and provided a uniquely defining property of the superconductor state. The ability for the expulsion effect is determined by the nature of equilibrium formed by the neutralization within the unit cell of a superconductor.
In the 1980s it was shown theoretically with the help of a disorder field theory, in which the vortex lines of the superconductor play a major role, that the transition is of second order within the type II regime and of first order (i.e., latent heat) within the type I regime, and that the two regions are separated by a tricritical point. [48]
Transition from ordinary conductivity (left) to superconductivity (right). At the transition, the superconductor expels the magnetic field and then acts as a perfect diamagnet. Superconductors may be considered perfect diamagnets (χ v = −1), because they expel all magnetic fields (except in a thin surface layer) due to the Meissner effect. [7]
a high-temperature superconductor levitating above magnet. Magnetic levitation is the most commonly seen and used form of levitation. This form of levitation occurs when an object is suspended using magnetic fields. Diamagnetic materials are commonly used for demonstration purposes.
Calculated magnetization curve for a superconducting slab, based on Bean's model. The superconducting slab is initially at H = 0. Increasing H to critical field H* causes the blue curve; dropping H back to 0 and reversing direction to increase it to -H* causes the green curve; dropping H back to 0 again and increase H to H* causes the orange curve.
Superdiamagnetism established that the superconductivity of a material was a stage of phase transition. Superconducting magnetic levitation is due to superdiamagnetism, which repels a permanent magnet which approaches the superconductor, and flux pinning, which prevents the magnet floating away. Superdiamagnetism is a feature of superconductivity.
Small magnet levitating above a high-temperature superconductor cooled by liquid nitrogen: this is a case of Meissner effect. An experiment based on flux quantization of a three-grain ring of YBa 2 Cu 3 O 7 (YBCO) was proposed to test the symmetry of the order parameter in the HTS.