SUPERCONDUCTING AND STRUCTURAL-PROPERTIES OF YBCO THIN-FILMS AND MULTILAYERS PREPARED BY OFF-AXIS PULSED-LASER DEPOSITION TECHNIQUE

We have studied the superconducting and structural properties of YBCO thin films and YBCO/STO/YBCO trilayers deposited on (100) SrTiO3 subst rates by off-axis PLD technique. The as-obtained c-axis oriented YBCO films show an excellent surface free of droplets or other irregulariti es as well as good structural and superconducting properties with T-c( R = 0) = 89 K, J(c) = 3 x 10(6) A/cm(2) (at 77 K and zero magnetic fie ld) and the Full Width at Half Maximum (FWHM) of the (005) YBCO rockin g curve of about 0.2 degrees. These structural and electrical propel t ies are very close to those of the YBCO films deposited by the convent ional PLD on-axis geometry. The TEM cross-sectional image shows that t he YBCO/STO/YBCO heterostructure has smooth interfaces and no short-ci rcuits or pinholes were observed. The electron diffraction analysis ha s revealed that both YBCO top and bottom layer as well as STO interlay er ape epitaxially grown with c-axis perpendicular to the substrate.