Superconducting characteristics of YBCO films

摘要

An investigation has been made of superconducting YBa/sub 2/Cu/sub 3/O/sub y/ (YBCO) thin films, which were prepared with two synthetic processes using RF-magnetron sputtering: (a) deposition at low substrate temperature with postannealing at around 900 degrees C, and (b) deposition at high substrate temperature around 650 degrees C with or without postannealing. High-T/sub c/ superconducting YBCO thin films were obtained with either process. The films prepared with process (a) had, however, poor J/sub c/ below 10 A/cm/sup 2/ at 77 K and their surfaces were rough. The films prepared with process (b) had higher J/sub c/ and smoother surfaces. Further improvement in surface morphology was made by raising substrate temperature to 700 degrees C at the start of the deposition.