Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 8: Postersitzung I: Supraleitung

TT 8.13: Poster

Montag, 8. März 2004, 14:30–19:00, Poster A

YBCO thin films prepared by a Fluorine-free sol-gel method — •C. Apetrii¹, I. v. Lampe², M. Falter¹, H. Schlörb¹, B. Holzapfel¹, and L. Schultz¹ — ¹IFW Dresden, Helmholtzstr. 20, 01069 Dresden — ²TU Berlin, Institut für Werkstoffwissenschaften und -technologien, Englische Str. 20, 10587 Berlin

The chemical solution deposition procedure is a low cost method due to non-vacuum approach for growing longer YBCO tapes. The polymer metal precursor technique, a fluorine-free sol-gel method, leads to a stable and non-aggressive precursor solution and also HF does not form during the process. HF is difficult to remove in precursor films prepared by the Trifluoracetates (TFA-method). Y, Ba, and Cu nitrates were chosen as a starting substances for the preparation of the polymer metal precursor to avoid the formation of BaCO₃. The polymer metal precursor films were produced by spin coating of a stoichiometric solution onto SrTiO₃ single crystal substrate and then dried at 170^∘C. The heat treatment was performed in a tube furnace with reaction temperature of 775^∘C. We obtained epitaxially grown 240 nm thick YBCO films on single crystal SrTiO₃ with a resistively measured T_c of 89.9 K and ΔT of 2.0 K. The temperature dependence of the critical current density was measured using the standard 4 point geometry on 20 µm wide bridges and values of 10⁵ A/cm² (at 77 K) were received.