Epitaxial Film Growth of Tl_0.78Bi_0.22Sr_1.6Ba_0.4Ca₂Cu₃O₉ on Rolling Assisted Biaxially Textured Nickel Substrates with YSZ And CeO₂ Buffer Layers

Abstract

Epitaxial film growth of Tl_0.78Bi_0.22Sr_1.6Ba_0.4Ca₂Cu₃O₉ ((Tl,Bi)-1223) on rolling assisted biaxially textured substrates with YSZ and CeO₂ buffer layers (RABiTS) has been successfully demonstrated by laser ablation and post-deposition annealing in flowing argon. X-ray diffraction (XRD) θ-2θ spectra showed that the films consisted mainly of c-axis aligned 1223 phase with some intergrown 1212 phase, while XRD Φ-scans of (102) pole figure revealed that the films are also a- and b-axes aligned, with an epitaxy of the «100» of (Tl,Bi)-1223 film on the «110» of the top YSZ buffer layer. Four-terminal electrical transport measurements showed that the zero-resistance transition temperature (T_c) was in the range of 106 - 110 K, and the critical current density (J_c) at 77 K and zero field was about 10⁵ A/cm² for the entire film width (3 mm) of a longer film (14 mm) which was processed differently from the shorter films (7 mm). For a shorter film (7 mm) that showed better ab-in-plane alignment, the magnetization J_c, at 77 K and extrapolated to zero field, calculated from Bean's model using the full film width (3.5 mm) as the appropriate lateral dimension, was 2 × 10⁵ A/cm².