Elimination of air detrimental effect using Tl-stabilized precursor for epitaxial HgBa 2CaCu 2O 6 thin films
The fabrication process for HgBa 2CaCu 2O 6+ δ (Hg-1212) superconducting thin films has been greatly simplified when an air-insensitive precursor film (Tl yBa 2CaCu 2O x) was employed. Using such precursors, high-quality Hg-1212 thin films have been reproducibly fabricated in air. X-ray diffraction θ-2 θ scans and pole figures show that these films consist of high-purity Hg-1212 grains that are c-axis oriented and in-plane aligned. Zero-resistance transition temperatures of these films are typically 122-124 K. Critical current density is up to 2.0×10 7 A/cm 2 at 5 K and remains above 1 MA/ cm 2 at 100 K in zero field.