High quality YBa2Cu3O7-δ films with controllable in-plane orientations grown on yttria-stabilized zirconia substrates.

The pulsed-laser deposition (PLD) technique was used to grow high T_C superconducting YBa₂Cu₃O_7-δ (YBCO) films on both virgin and ion-bombarded yttria-stabilized zirconia (YSZ) substrates. To pattern high T_C films for device applications, the ion milling technique is often used to turn virgin YSZ substrates into ion-bombarded substrates. Multilayered processes require the growth of high T_C films on these ion-bombarded substrates. The purpose of this work was to investigate the growing conditions for these two kinds of substrate surfaces. We found that high quality 0° in-plane orientation films can be grown on either substrate when the growth temperature is about 810 °C. The thin film grown at this temperature has T_C of about 90.3 K and J_C of about 4×10⁶ A cm^-2 at 77 K. On virgin substrates, the in-plane orientations of YBCO films grown within the temperature range of 790–730 °C exhibit a mixture of 0° and 45° domains. As the growth temperature decreases, the dominant orientation shifts gradually from 0° to 45°. On the other hand, on ion-bombarded YSZ substrates, the in-plane orientation of YBCO films grown within the same temperature range shows that the 45° domain is more prominent. Furthermore, 9° subpeaks appear around the 0° peak on ion-bombarded YSZ substrates. At a lower growth temperature of around 690 °C, only the 45° domain exists on the virgin substrate, while a small amount of 0° domain is present with the majority of 45° domain on the ion-bombarded substrate. The T_C and J_C of the films grown at around 690 °C on virgin substrates are as good as films grown at high temperatures, despite the difference in the in-plane orientations. [ABSTRACT FROM AUTHOR]