A Brief Overview on the Chronological Development on Superconductivity

Superconductors have zero resistance in electrical conductivity below their transition temperatures. Due to this property, these devices are used frequently in different fields. For producing superconductors of low transition temperatures, costly coolants are required. So researchers are involved to produce superconductors of high transition temperatures, hi the first part of this paper, an overview of superconductivity and its basic properties are described. This part also contains the chronological development and evolution of superconducting phenomena in both conventional and high temperature superconductors. Properties and crystal structure of High Temperature Superconductors (HTSC) are also discussed. In the second part of the paper, report on the research work done by the author is briefly stated. It is established that A C conduction of charge carriers in HTSC samples occurs through both tunneling and hopping. The AC Universality of the HTSC samples is shown and it confirms the basic transport process in the normal state like other polycrystalline materials.