The vortex glass theory has been successfully employed to describe the vortex phase state of high TC superconductors (HTSCs). Its validity can be examined by scaling the current–voltage isotherms with appropriate exponents and a universal scaling function. However, this second order phase transition model is not applicable for the layered superconductor Cu0.03TaS2 due to its weak pinning, which could be proved by the peak effect in the M–H loop. Finally, we give the different pinning echanisms with H‖ab and H‖c. Vortex strings and pancake vortices are formed under parallel and perpendicular magnetic fields, respectively. The vortex strings are pinned by normal layers in layered superconductors, while the pancake vortices are connected by Josephson coupling.

Related Links: http://iopscience.iop.org/0953-2048/24/7/075006