For the formation of epitaxial superconducting Tl0.78Bi0.22Sr1.6Ba0.4Ca 2Cu3O9-δ((Tl,Bi)-1223) thin films, the dependence of phase development on the chemical state of the source materials, deposition distance from source to substrate, and O2 pressure during deposition by laser ablation and post annealing was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). It was found necessary to have thallium in the precursor film and that a reacted source target is better than the unreacted source for obtaining (Tl,Bi)-1223 phase-pure films. Better (Tl,Bi)-1223 films were obtained at a deposition distance of 44 mm from source to substrate than at a distance of 61 mm over a range of O2 pressure from 5.7 to 31.3 mTorr The best films prepared under the optimal conditions exhibited transport Jc close to 3 × 106 A/cm2 at 77 K and zero field.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering