RF plasma deposition and in-situ property enhancement of Bi 2Sr 2Ca n−1Cu nO x thin films

Abstract

An atmospheric pressure, inductively coupled, argon-oxygen RF plasma process has been used to prepare, in-situ, superconducting Bi 2Sr 2Ca n−1 Cu n O x thin films. Film properties have been enhanced by exposing the grown film, in-situ, to the same argon-oxygen plasma used for its deposition. This is achieved by switching off the atomized precursor nitrate solution to the plasma torch. T c's of 76 K and J c's of 1.3 × 10 5 A/cm 2 at 60 K and zero field have been achieved in the in-situ, Bi 2Sr 2Ca 1Cu 2O x films. Bi 2Sr 2Ca 2Cu 3O x films with T c's of 100 K and J c's of 1 × 10 5 A/cm 2 at 77 K and zero field have also been grown. The effects of film exposure to the plasma for different time periods and RF power levels are discussed. The effects of deposition parameters, such as substrate temperature, bismuth content, solution concentration and phase control, are analyzed. Finally, the critical current behavior of the films under a external magnetic field of up to 5 T is reported.