YBA2CU3O7 THIN-FILMS GROWN ON SAPPHIRE WITH EPITAXIAL YTTRIA-STABILIZED ZIRCONIA BUFFER LAYERS

Epitaxial yttria-stabilized zirconia (YSZ) buffer layers were grown successfully on sapphire (1120BAR) substrates by using rf magnetron sputtering method. The films were cubic in structure with their (100) orientation normal to the substrate surface. YBa2Cu3O7 thin films were deposited on the YSZ/sapphire substrates by the in situ dc magnetron sputtering method. X-ray diffraction analysis showed they were highly c-axis oriented with the zero resistance temperature T(CO) = 92 K and critical current density J(c) = 1.6 X 10(6) A/cm2 at 77 K.