Substrate temperature dependence of the texture quality in YBCO thin films fabricated by on-axis pulsed-laser ablation

In applications of superconducting devices, the crystalline texture of high-quality YBa2CU3O7-x thin films is of primary importance. The preferred orientation of the films can be essentially controlled by means of the substrate temperature, T-s. in order to study the dependence of the film texture on different T-s, a series of films were deposited on YSZ substrates by the on-axis pulsed-laser ablation technique. The substrate temperature was varied from 600 degrees C to 800 degrees C while the rest of the growth parameters remained the same. Various analytical techniques, including x-ray diffraction, scanning electron microscopy, micro-Raman spectroscopy and the four-point probe method, were applied to characterize the films. At around T-s, = 700 degrees C, the best films with the smoothest surface morphology, lowest FWHM of the rocking curve and highest in-plane texture were obtained. The resultant J(c) in excess of 1 x 10(6) A cm(-2) at 77 K and T-c around 91 K were also achieved at this temperature.