Comparison of pinning parameters between low-Tcsuperconductors andYBa2

Plasticity and Memory Effects in the Vortex Solid Phase of TwinnedYBa2Cu3O7Valenzuela1, Bekeris2 2000Phys. Rev. Lett.596720View full textAdd to dashboardCite

“…History effects recently observed in conventional low-T c superconductors [6,9,10,12] were attributed to plastic deformations of the VS; however, little is known about the exact mechanism involved in these phenomena. In YBa 2 Cu 3 O 7 (YBCO), the importance of plasticity has been revealed through magnetic [8,[13][14][15] and transport [16] measurements below the melting transition, though detailed history effects studies have not been performed up to now.In this Letter we report on thermomagnetic history effects in the solid vortex phase of pure twinned YBCO single crystals by measuring the ac susceptibility with the ac field parallel to the c axis of the sample. ac susceptibility is a sensitive tool to detect changes in J c and, therefore, in the translational correlation length of the VS. Our results show that the VS may be trapped in different metastable states depending on its thermomagnetic history.…”

“…History effects recently observed in conventional low-T c superconductors [6,9,10,12] were attributed to plastic deformations of the VS; however, little is known about the exact mechanism involved in these phenomena. In YBa 2 Cu 3 O 7 (YBCO), the importance of plasticity has been revealed through magnetic [8,[13][14][15] and transport [16] measurements below the melting transition, though detailed history effects studies have not been performed up to now.…”

Microcomposites based on superconducting cuprates

“…27 Enhancement of pinning due to heat treatment and mechanical treatment can be exemplified by the formation of a finegrained material based on Nb 3 Sn (Ref. 20) and epitaxial HTSC films less than 1 mm thick. The maximum critical current densities for such films reach nearly 10 5 ± 10 6 A cm 72 at 77 K, which can be explained by high concentration of dislocations at small-angle boundaries of submicrometre-sized domains.…”

Flux vortex dynamics in type-II superconductors

“…Typically, measurements of the Campbell penetration depth have been used to establish the magnetic field profiles for small applied magnetic fields in order to probe the current density profile close to the superconductor surface [5]. Additionally, as the value of λ C will be determined by the pinning centre size, d, the method can be used to establish the effective size and dependence on DC magnetic field of the pinning potential [6]. Hence, a closely related quantity, the Labusch parameter [7], which is the effective curvature of the pinning potential, can be determined.…”