Thin TlBa2Ca2Cu3O9+x. films were grown on single crystal (110) LaAlO3 from metal-organic chemical-vapor deposition-derived Ba-Ca-Cu-Ox precursor films employing Ba(hfa)2·mep, Ca(hfa)2·tet, and Cu(dpm)2 (hfa=hexafluoroacetylacetonate; dpm=dipivaloylmethanate; tet=tetraglyme; mep=methylethylpentaglyme) as the volatile metal sources. Thallination is then accomplished by annealing the precursor films in the presence of a bulk BaO+CaO+CuO+TlF source at 885°C in flowing O2. The presence of TlF is essential for nucleating the Tl-1223 phase. The resulting Tl-1223 films are nearly phase-pure, highly oriented, epitaxial by x-ray diffraction, and contain negligible fluoride by windowless energy-dispersive x-ray measurements. The films exhibit a transport measured Tc = 103 K and Jc = 4.4 × 104 A/cm2 (77 K, 0 T). Magnetic hysteresis measurements yield Jc = 1.9 × 105 A/cm2 (30 K, 0.01 T) and show considerable flux pinning at low temperatures with Jc = 1.4 × 105 A/cm2 (5 K, 4.5 T).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)