Superconductivity

Definition of superconducting superconductivity Superconductivity is a phenomenon exhibited by a specific conductor and indicates resistance to current. A conductor is a material through which an electron current passes. There are four different conductors. Insulators such as glass and wood have very high electrical resistance, but semiconductors (silicon etc) have moderate electrical resistance. Conductors such as copper and other metals have very low electric resistance, superconductors are made of specific metals (ceramics such as mercury and yttrium - yttrium - copper - oxide), and there is no electric resistance.

Superconducting materials can transport electrons without resistance and therefore do not emit heat, sound or other forms of energy. Superconductivity occurs at the critical temperature (T) of a particular material. As the temperature decreases, the electrical resistance of the superconducting material gradually decreases until it reaches the critical temperature. At this point the resistance drops as shown to the right, usually zero. Currently, most materials must reach a very low energy state via cold and / or high pressure to achieve superconductivity. Studies on superconductors effective at high temperatures are under development, but superconductivity can usually only be achieved through expensive and inefficient cooling processes.

In the superconducting material, when the temperature T is lower than the critical temperature Tc, superconducting characteristics are generated. The value of this critical temperature depends on the material. Conventional superconductors typically have a critical temperature of about 20 K to less than 1 K. For example, the critical temperature of solid mercury is 4.2 K. As of 2015, a high pressure of about 90 gigapascals is required, but the highest critical temperature of conventional superconductors is 203 K for H 2 S. Copper oxide superconductors can have a higher critical temperature. YBa 2 Cu 3 O 7 is one of the first discovered copper superconductors with a critical temperature of 92 K. The interpretation of these high critical temperatures is not yet known