Dislocation Density and Critical Current Density of Sm_1+xBa_2-xCu₃O_y Films Prepared by Various Fabrication Processes

Abstract

Dislocations are effective flux-pinning centers in REBa2Cu3Oy films at a magnetic field. To investigate the relationship between critical current density (Jc) and dislocation density, we discussed the dislocations in conventional pulsed-laser-deposition (PLD)-SmBCO films, vapor–liquid–solid (VLS)-SmBCO films, and low-temperature growth (LTG)-SmBCO films. The LTG-SmBCO and VLS-SmBCO films showed high-Jc at low magnetic fields. From the observation of etch pits, we found that the LTG-SmBCO and VLS-SmBCO films had high-dislocation densities. We speculate that Jc at low-magnetic fields is affected by dislocation density. LTG is effective for increasing dislocation density without deteriorating crystallinity or superconducting properties.