Critical current measurements in YBa2Cu3O7−x thin film grown on LaAlO3 substrate

Abstract

The critical current density Jc(B,T) of epitaxial YBa2Cu3O7−x (YBCO) thin films on LaAlO3 was measured under different applied magnetic fields (0–7 T) with the temperature ranging from 65 to 79 K. At 65 K, the zero-field critical current density of the best film was 5.8×106 A/cm2; even at magnetic fields up to 7 T, Jc could reach as high as 1×106 A/cm2. Strong anisotropy was observed at 79 K. The anisotropy behavior diminished with the decrease of temperature. Experimental results showed that Jc was proportional to (Tc−T)3/2 ; this was in accordance with the theoretical explanation by the Josephson junction model for granular superconductors.

Synthesis, Structure, and Magnetic Characterization of Pulsed Laser-Ablated Superconducting La2CuO4Fx Thin Films

“…This is a respectable value, but other superconducting copper oxide systems have superior J c characteristics (e.g., optimally grown thin films of YBa 2 Cu 3 O 7 - δ possess zero field J c values of ca. 5 × 10 6 A cm -2 at a temperature of 77 K).…”