Fabrication and characterization of BaxSr1-xTiO3/YBa(2)Cu3O(x)/SrTiO3 structure

Abstract

BaxSr1-xTiO3 (BST)/YBa2Cu3Ox (YBCO)/SrTiO3, (STO) structures were deposited, and the microstructure. orientation and electrical characteristics Acre investigated. (001) oriented YBCO thin films were deposited on STO substrates using pulsed laser deposition. and (h00) oriented BST thin films were deposited on YBCO/STO Substrates using electron cyclotron resonance (ECR) plasma assisted metal organic chemical vapor deposition (MOCVD). A new phase as formed at the interface between YBCO and BST films and was speculated to be (BaxY1-x)(TiyY1-y)O-3. Ba-rich BST films showed a higher dielectric loss than Sr-rich BST films did. which indicates that Sr-rich BST films are more suited for application to microwave devices. The dielectric loss of the films was reduced as temperature decreased. which may be due to the conductivity change of YBCO film and the formation of a conduction path rather than a dielectric property change of the BST film itself. The capacitance vs voltage and the dielectric loss vs bias voltage curves of BST film showed a polarity dependence, which may be speculated to be because of the barrier height difference between the interfaces.