IMPROVEMENT OF THE CONDUCTING PARAMETERS OF YBA2CU3OX FILMS GROWN ON SAPPHIRE THROUGH THE USE OF A STRONTIUM-TITANATE BUFFER LAYER

High-T-c superconducting films of YBa2Cu3Ox on sapphire with an additi onal buffer layer of strontium titanate (actually, on heterostructures (100)SrTiO3/(001)YBa2Cu3Ox/(100)CeO2/(1 (1) under bar 02)Al2O3) are o btained by laser deposition, and their superconducting characteristics are investigated. It is shown that that buffering the sapphire by a s trontium titanate film can raise the critical temperature of the YBa2C u3Ox films by two degrees and give a severalfold increase in the criti cal current density. (C) 1998 American Institute of Physics.