Vortex Pinning/Dynamics in YBCO Films with J_c(77K)>3·10~6 A/cm~2 Studied by Direct Transport Measurements

摘要

Critical current density, J_c, is studied for highly biaxially-oriented YBCO thin films with J_c(77K)>3 MA/cm~2 in a range of magnetic fields, temperatures, angles between magnetic field vector and film c-axis. J_c(H,θ) is shown to be dominated by vortex interaction with high density (>10~(11) lines/cm~2) of linear pins — edge dislocations. A model is developed to describe different vortex arrays behavior in the presence of two-dimensional square network of linear pins.