Synthesis of thick YBCO films up to 3.0 m on metallic substrates by a fluorine-free metal organic decomposition method

We improved the critical current properties of fluorine-free metal organic decomposition processed YBCO thin films prepared on buffered metallic substrates by increasing the thickness of the films. YBCO films prepared using a conventional one-time growth exhibit a maximum Ic (77 K, ∼0 T) value of ∼100 A per 1 cm width for a film with a thickness of 0.8 m, and Ic decreases with further increases in the film thickness due to the generation of impurity particles and micro-cracks. In this study, a multiple growth process was adopted for the preparation of thick films to avoid these problems. The Ic of films prepared using this method monotonically increased with the film thickness. YBCO films with a thickness of ∼3.0 m recorded a quite high Ic (77 K, ∼0 T) value for ∼210 A cm−1 width. Additionally, the in-field Jcs at 20 K and 40 K were found to increase almost proportionally to the film thickness.