Superconductivity

Name:
Superconductivity
Detailed information:
The phenomenon in which certain metals, alloys, and compounds at temperatures usually near absolute zero lose both electrical resistance and magnetic permeability, i.e., have infinite electrical conductivity. Depending upon the substance, the maximum temperature (transition temperature) for the phenomenon as of 1985 was 0.5–28K. Superconductivity does not occur in alkali metals, noble metals, ferro- and antiferromagnetic metals. It is well known in elements having 3, 5, or 7 valence electrons per atom, and is associated with high room-temperature resistivity. A system for transmitting electric current underground by means of superconducting cables has been developed.See Cryogenics.