Explanation

Some metals, semiconductors, multi-component metal oxides, alloy have the characteristic of zero resistivity at low temperatures, and objects with superconductivity are called superconductors. The two basic characteristics of superconductors are zero resistance and Meissner effect. The zero resistance characteristic means that the resistivity of the superconductor rapidly drops to zero when the temperature is one lower than a certain temperature (called the critical temperature). Below this temperature, the superconductor does not have the observed DC resistance. The Meissner effect refers to that when a magnet is close to a superconductor in a superconducting state state, the magnetic field of the magnet will cause superconducting current to appear on the surface of the superconductor. The magnetic field formed by this superconducting current is exactly the same size as the magnetic field of the magnet inside the superconductor. In the opposite direction, the magnetic induction intensity inside the superconductor is zero. Whether the superconductor is first applied with a magnetic field, and then cooled to become a superconducting state state, or first cooled to become a superconducting state state, and then applied with a magnetic field, the strength of the magnetic field in the superconductor in the superconducting state state is always zero.

Classification