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Pure Bi 2 Sr 2 Ca 2 Cu 3 O x (Bi-2223) phase is hard to be achieved in Bi-2223 thin films fabricated by using chemical solution deposition (CSD) due to the volatilization of specific elements. Two protected sintering methods were proposed in this work to enhance the phase purity of CSD Bi-2223 thin films. One method is two deposited thin films stacked "face-to-face" (FTF) and then sintered. A "substrate/precursor film/precursor film/substrate" architecture was used during sintering instead of common "precursor film/substrate" architecture. The other method was named "sealed face-to-face" (SFTF). The FTF structure was buried in Bi-2223 powders and then sealed in a silver envelope before sintering. Different sintering temperature and sintering time were investigated in an 8% O 2 (N 2 balance) atmosphere. The volume fraction of Bi-2223 phase could be enhanced to 17% by using the FTF method, and 68% by using the SFTF method.

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In this study, biaxially textured (Bi, Pb)2Sr2Ca2Cu3Ox ((Bi, Pb)-2223) thin films were fabricated epitaxially on LaAlO3 (LAO) single crystal substrates via the chemical solution deposition (CSD) method. In order to prevent the evaporation of Bi and Pb, a sealed face-to-face architecture for sintering was utilized. According to the results of x-ray diffraction measurements including θ/2θ-scan, ω-scan, and ϕ-scan patterns, the optimal sintering temperature was found to be 840 °C. The volume fraction of the (Bi, Pb)-2223 phase of the optimal sample was enhanced to above 80%. Favorable out-of-plane and in-plane textures were also detected, which could be attributed to an epitaxy system of (Bi, Pb)-2223 thin film and an LAO substrate with a 45° rotated alignment. A dense microstructure and thickness of about 100 nm were found by scanning electron microscopy observations of the surface morphology and cross section. The critical temperature of the optimal sample determined with the four-probe method was 103.2 K, and its critical current density values were 0.06 MA cm−2 (77 K, self-field) and 1.91 MA cm−2 (4.2 K, self-field), which were obtained by AC susceptibility measurement and a superconducting quantum interference device, respectively. This study demonstrated the feasibility of fabricating (Bi, Pb)-2223 thin films with superconducting performance via the low-cost CSD method.