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An optimized buffer layer architecture prepared by a metal organic deposition method on biaxially textured metallic substrate is proposed and developed successfully. The major achievement of this work is to choose a Ce 0 9 La 0 1 O 2 layer as cap layer that possesses an excellent lattice match with the superconductor layer, and to employ 200 nm thick Gd 2 Zr 2 O 7 film as barrier layer. The effect of thermal cycling on the texture and morphology of the crystallized films and NiW substrate is discussed in detail. The texture quality and the epitaxial relationship between the buffer layer stack and the metallic substrate were studied by synchrotron x-ray diffraction. Well textured, smooth and crack-free Ce 0 9 La 0 1 O 2 Gd 2 Zr 2 O 7 buffer layer stacks are obtained, demonstrating the possibility of producing a high quality buffer layer stack by a low cost chemical solution deposition route.

The possibility of using spray pyrolysis as a simple, chemical, low cost method for the production of CeO 2 and MgO thin films widely used as buffer layers for second generation coated conductors was examined. CeO 2 films were produced on borosilicate glass substrates and four different surface morphologies were observed at different deposition temperatures. The smoothest films were obtained when the process was described as low temperature chemical vapour deposition. In addition, c-axis textured CeO 2 films have been deposited on Si (100) single crystal, but the surface morphology was quite rough, consisting of distinct particles indicating that further optimisation is needed. On the other hand c-axis textured MgO films with smooth morphologies were deposited on Si (100) single crystal. Rocking curves revealed an excellent out of plane texture with a FWHM between 0.95 0 and 1.01 0

Pulsed laser deposition (PLD) was used to deposit YBCO on MgO-buffered C276 substrates in order to evaluate the quality of the deposited MgO films which were deposited by spray pyrolysis. The characterization of the thin films was done using scanning electron microscopy, atomic force microscopy, electron backscattered diffraction, X-ray diffraction 2θ -scans, rocking curve (ω-scans), phi scan, pole-figure measurements, and AC susceptibility. It was found that c-axis oriented YBCO films were grown on c-axis oriented MgO films which confirm that the deposited YBCO films copied the out-of-plane texture of the spray pyrolyzed MgO buffer. However, MgO and YBCO films have a very weak in-plane texture. The AC susceptibility measurements show that the YBCO films have a broad superconducting transition temperature which may be attributed to the weak in-plane texture.

Spray pyrolysis was used to deposit MgO films on polycrystalline 321-austentic stainless steel substrates using magnesium nitrates and magnesium acetates as precursors. The MgO films deposited from the nitrate precursors were amorphous; however, MgO (200) oriented films were obtained when the acetates precursors were used. The texture of the films was improved with increasing the concentration and the deposition temperature. To evaluate the performance of the MgO buffers, PLD was used to deposit YBCO on MgO-buffered 321 substrates. Only the smoothest MgO films were found as good buffers for the deposition of c-axis oriented YBCO films. The superconducting transition temperature was broad and the T C onset was 83.6 K. Austenitic 321 steel is an alternative for C276 as a substrate for thin film deposition.