Vortex pinning landscape in YBa2Cu3O7films grown by hybrid liquid phase epitaxy

The influence of film thickness and growth rate on the vortex pinning in hybrid liquid phase epitaxy (HLPE) films was explored. Film growth rates as high as 12 nm s −1 (0.7 µm min −1 ) produced high J c films. Weak or no thickness dependence was found in films of thickness ranging from 0.4 to 3 µm. Field and angular measurements of the critical current density ( J c ) and the power-law exponent ( N ) of the current–voltage curves were used to determine the nature of pinning. Films thinner than 0.6 µm showed a higher density of correlated defects parallel to the ab plane than thicker films. Using HLPE, it was possible to achieve very strong pinning in films ∼3 µm thick, yielding critical currents over 300 A cm −1 width at self-field , and as high as 35 A cm −1 width at μ 0 H = 3 T at T = 75.5 K. Decreasing the deposition rate allowed improving the high field performance, opening up the possibility to engineer the pinning landscape of the HLPE films.