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Growth of epitaxial Ba2YCu3O7−x films on LaAlO3 (001)

1990; Elsevier BV; Volume: 172; Issue: 3-4 Linguagem: Inglês

10.1016/0921-4534(90)90618-o

1873-2143

Michael P. Siegal, Julia M. Phillips, Yong-Fen Hsieh, John Marshall,

Advanced Condensed Matter Physics

We report the ex situ growth of 1000 and 2000 Å epitaxial Ba2YCu3O7−x (BYCO) filmsonLaAlO3 (001 with surface morphologies and crystallinity generally associated with high quality in situ films. Films are grown by co-depositing BaF2, Y and Cu in a stoichiometric ratio within 1% of 2:1:3, followed by annealing in a two-stage process in a tube furnace. By optimizing the annealing conditions, excellent crystallinity is obtained, with χmin∼ 2–4] from Rutherford backscattering/channeling. These films have sharp superconducting resistance transitions at 90–91 K. Critical current densities at 77 K are ∼ 106 A/cm2 in zero magnetic field and ⪅ 105 A/cm2 in H=0.9 T oriented perpendicular to the ab plane of the films.