Epitaxial thin films of YBaCuO have been prepared with (1) the a axis perpendicular to (100) SrTiO3; (2) the c axis perpendicular to (100) SrTiO3; and (3) the  axis perpendicular to (110) SrTiO 3. Films were fabricated using a multilayer deposition technique involving three electron guns containing Y, BaF2, and Cu under a pressure of 5×10-5 Torr of O2. As deposited films, which contained polycrystalline and amorphous regions, were later annealed in a furnace under a flowing O2-H2 O atmosphere. X-ray diffraction patterns as well as scanning electron microscopy and high-resolution electron microscopy images confirm that the films are highly oriented, essentially epitaxial. The a-axis oriented film exhibits zero resistance at 90 K and a critical current density of 2.9×106 A/cm2 at 4.2 K while the c-axis oriented film exhibits a T c of 88 K and a Jc of 0.9×107 A/cm 2 at 4.2K; the Jc values were determined magnetically. The -orientation film shows the sharpest transition with a transition width of 1 K and zero resistance at 85 K.
ASJC Scopus subject areas
- Physics and Astronomy(all)