This project was focused on a basic scientific problem, one that is at the heart of application and development of superconductivity for efficient energy usage. This is improvement in high current density which can only be achieved by learning to pin vortices to the physical structure of its underlying superconducting material. Quantized vortices are the tornado of electrical supercurrents, ubi...

HISTORY OF HIGHTEMPERATURE SUPERCONDUCTIVITY After superconductivity was discovered by Onnes in 1911, many superconductors were discovered and the critical temperature rose year by year. More than 2000 superconducting materials had been discovered by 1975, and the critical temperature had reached 22.3 K with the discovery of Nb3Ge in 1973. After that, however, no higher critical temperature was...

By tuning morphology and size of magnetic subsystem, ferromagnet-superconductor (F/S) hybrid system provides an effective way to modulate superconductivity due to the interaction between superconducting and magnetic-order parameters at the mesoscopic length scale. In this work, we report on investigations of critical current density in a large-area Co/Nb hybrid via facile colloidal lithography....

Nearly hydrostatic pressures are found to enhance the critical current density Jc through single grain boundaries in YBa2Cu3Ox rings and to induce superconductivity in Li. Whereas Li becomes superconducting above 20 GPa at temperatures as high as 15 K, no superconductivity was observed above 4 K in Na to 65 GPa nor in K above 4 K to 43.5 GPa or above 1.5 K to 35 GPa.

We investigate the relation of the critical current density (Jc) and the remarkably increased superconducting transition temperature (Tc) for the FeSe single crystals under pressures up to 2.43 GPa, where the Tc is increased by ~8 K/GPa. The critical current density corresponding to the free flux flow is monotonically enhanced by pressure which is due to the increase in Tc, whereas the depinnin...