EPITAXIAL YBA2CU3O7-DELTA-AG THIN-FILMS (J(C)=6X10(6) A CM(2)) ON EPITAXIAL-FILMS OF BA2LANBO6, A NEW PEROVSKITE SUBSTRATE, BY PULSED-LASERABLATION/

Ba2LaNbO6, a new perovskite ceramic substrate material for YBa2Cu3O7-d elta has been grown epitaxially on (100) LaAlO3 from a sintend Ba2LaNb O6 pellet by pulsed laser ablation. The optimum substrate temperature for the epitaxial growth of Ba2LaNbO6 on LaAlO3 was found to be 780 de grees C for a laser energy density of 2.6 J/cm(2). The epitaxial natur e of the Ba2LaNbO6 film was confirmed by X-ray diffraction and AFM stu dies. A superconducting YBa2Cu3O7-delta-Ag film grown in situ on epita xial Ba2LaNbO6 film gave T-c(0) = 90 K with a sharp transition of Delt a T = 0.4 K. The YBa2Cu3O7-delta-Ag films exhibited excellent (001) or ientation of an orthorhombic YBa2Cu3O7-delta phase and showed almost p erfect metallic behaviour in the normal state with resistance ratio (R -300 K/R-100 K) = 2.95. Critical current density of 6 x 10(6) A/cm(2) at 77 K was consistently obtained for the YBa2Cu3O7-delta-Ag films dep osited on epitaxial Ba2LaNbO6 films. The implications are discussed. ( C) 1997 Elsevier Science B.V.