CRYSTAL ORIENTATION CONTROL OF YBA2CU3O7-X THIN-FILMS PREPARED BY PULSED-LASER DEPOSITION

We have investigated the effect of deposition rates on the film orient ation and superconducting properties of the grown films. YBa2Cu3O7-x t hin films were fabricated on LaSrGaO4(100) substrate by a pulsed laser deposition. A trend of decreasing c-axis oriented growth as the depos ition rate increased was revealed by x-ray diffraction. A cubic phase with a lattice parameter of 0.39 nm has been formed at above 10 Hz rep etition rate at 700 degrees C substrate temperature. We conclude that cubic phase formation is prior to c-axis or a-axis oriented orthorhomb ic phase formation at high supersaturation condition owing to a kineti c limitation.