Y-Ba-Cu-0 (YBCO) superconducting films were prepared on SrTiO3(100) substrates by metalorganic chemical vapor deposition. The precursors used were β-diketone chelates of Y, Ba and Cu. The YBCO films, having superconducting transition temperature defined by zero resistivity (Tc(R=0)) above 90 K and critical current density (Jc) over 106 A/cm2 at 77 K and 0 T, were obtained at the conditions of oxygen partial pressure (Poj) and deposition temperature (Tdep) near the CuO-Cu2O-O2equilibrium line (PO2=3.6 Torr-Tdep= 850°0 and PO2=0.036 Torr - Tdep=700-720°C). The films prepared at these conditions showed Jc over 104 A/cm2 at 77 K in high magnetic fields above 20 T. The nano-composite structure of the YBCO films was studied by transmission electron microscopy. CuO and Y2Cu205 grains with a size of 0.1-2 µm were included. The precipitates of about 10 nm in size were observed in the matrix of the YBCO films.
|ジャーナル||journal of the japan society of powder and powder metallurgy|
|出版ステータス||Published - 1994 2 1|
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