New model of the pinning potential barrier in layered HTc superconductors

New model of the pinning potential barrier in multilayered HTc superconductors is presented, based on geometrical approach to the capturing interaction of pancake-type vortices with nano-sized defects. Using the above model the transport current flow phenomena in these materials, especially the current–voltage characteristics and critical current density, have been considered. Details of theoretical analysis are given, including the derivation of basic mathematical equations describing the potential barrier as a function of transport current intensity and the initial position of captured pancake vortex. Computer simulation has been performed of the influence of transport current amplitude on the potential barrier height for various sizes of pinning centers and initial pancake vortex position as well as the influence of fast neutrons irradiation creating nano-sized defects on critical current of HTc layered superconductor.

New approach to pancake vortices interaction with nanosized defects in HTc superconductors

In this paper, an elaborated new theoretical model of the interaction of pancake-type vortices with nanosized defects is presented based on the energy gain analysis of the captured pancake vortices in nanosized defects in multilayered HTc superconductors. Current–voltage characteristics have been calculated in static and dynamic cases and compared with experimental data. Dynamical anomalies have been then predicted based on the solution of magnetic diffusion equation, which also well correspond to our previous experimental data.

Impact of the Magnetic Flux Penetrating Vortex Core on the Critical Current of the HTc Superconductors

New model of the capturing vortices in the HTc superconductors is presented, describing their electromagnetic properties, such as the critical current of these materials. Critical current of the superconductors, such as HTc tapes is dependent on the magnitude of the interaction magnetic vortices with pinning centers. This is in fact quantum effect since the magnetic flux in vortices is quantized. Capturing the vortices on the normal state nano-sized inclusions should lead to the modification of the flux distribution in the vortex core depending on the vortex position in the respect to the pinning center edge. These effects are considered in the paper and their influence on the critical current of the HTc materials, basing on the new model of the pinning interaction.