When any material loses its resistance for electric current, then it is called superconductor, Kammerlingh Onnes (1913) observed this phenomenon at 4K in mercury. The materials offering no resistance to the flow of current at very low temperature (2-5K) are called superconducting materials and phenomenon is called superconductivity.
Examples, Ge alloy (Before 1986)
Following are the important applications of superconductivity,
(b) Building supermagnets,
(c) Aviation transportation,
(d) Power transmission
“The temperature at which a material enters the superconducting state is called the superconducting transition temperature, ”. Superconductivity was also observed in lead (Pb) at 7.2 K and in tin (Sn) at 3.7K. The phenomenon of superconductivity in other materials such as polymers and organic crystals. Examples are
(SN)x, polythiazyl, the subscript x indicates a large number of variable size.
(TMTSF)2PF6, where TMTSF is tetra methyl tetra selena fulvalene.