Related papers: Dynamic Aspects of Strong Pinning
Mechanisms of vortex dynamics and pinning and self-field effects which could account for the thickness dependence of the critical current density J_c of superconducting films are addressed. It is shown that at low magnetic fields B, the 2D…
We propose to use superconductor-magnet multi-layer structure to achieve high critical current density by invoking polaronic mechanism of pinning. The magnetic layers should have large magnetic susceptibility to enhance the coupling between…
We present a study of the magnetic response of Type-II superconductivity in the extreme pinning limit, where screening currents within an order of magnitude of the Ginzburg-Landau depairing critical current density develop upon the…
The addition of artificial pinning centers has led to an impressive increase in critical current density ($J_{\rm c}$) in a superconductor, enabling record-breaking all-superconducting magnets and other applications. $J_{\rm c}$ has reached…
We analyze the effects of demagnetizing fields in the magnetization hysteresis loops of type-II superconductors, by a model that allows the calculation of current and field profiles in finite cylindrically symmetric superconductors in the…
We present a comprehensive investigation of the field-dependent critical current density and pinning force, combined with a detailed analysis of the nanostructural defect landscape in single crystal of underdoped PrFeAs(O,F) superconductor.…
Pinning and thermal creep determine the response of numerous systems containing superstructures, e.g., vortices in type II superconductors, domain walls in ferroics, or dislocations in metals. The combination of drive and thermal…
\\A simple model for a superconductor with tunable critical current is studied theoretically. The model consists of a thin superconducting film with one vortex interacting with one magnetic dipole, whose magnetic moment is free to rotate,…
We identify a phase transition in the vortex system of a high-temperature superconductor with nano-columnar stacks of precipitates as strong vortex pinning centers. Above a particular, temperature-dependent field $B_X(T)$ the vortex…
A series of polycrystalline SmFeAs1-xOx bulks was prepared to systematically investigate the influence of sample density on flux pinning properties. Different sample densities were achieved by controlling the pelletizing pressure. The…
We present a comprehensive overview of vortex pinning in single crystals of the isovalently substituted iron-based superconductor BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$, a material that qualifies as an archetypical clean superconductor,…
We examine vortex pinning and dynamics in thin-film superconductors interacting with square and rectangular pinning arrays for varied vortex densities including densities significantly larger than the pinning density. For both square and…
The critical state problem in type-II superconductivity is described theoretically by a direct optimization method, which allows a straightforward treatment for non idealized geometries. Based on Faraday's law and the principle of minimum…
Dependence of the critical current $I_c$ on the applied magnetic field $H_a$ is theoretically studied for a thin superconducting strip of a rectangular cross section, taking an interplay between the Bean-Livingston and the geometric…
We discuss predictions of five proposed theories for the critical state of type-II superconductors accounting for both flux cutting and flux transport (depinning). The theories predict different behaviours for the ratio $E_y/E_z$ of the…
We have studied vortex pinning and dynamics in a Sr0.6K0.4Fe2As2 superconducting tape with critical current density Jc~0.1 MA/cm2 at 4.2 K and 10 T. It is found that grain boundary pinning is dominant in the vortex pinning mechanism.…
Local magnetic measurements are used to quantitatively characterize heterogeneity and flux line pinning in PrFeAsO_1-y and NdFeAs(O,F) superconducting single crystals. In spite of spatial fluctuations of the critical current density on the…
An exact analytical solution is given for the critical state problem in long thin superconductor strips in a perpendicular magnetic field, when the critical current density j_c(B) depends on the local induction B according to a simple…
The critical current density has been measured on single crystals of Ru substituted BaFe2As2 superconductor at several temperatures and in fields up to 16 T. The magnetisation versus field isotherms reveal the occurrence of a clear second…
Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear…