PrBa2CU3_yNbyO7_Z Insulating Films for YBa2Cu3O7-Y Based High TCElectronics

We have characterized the structural and transport properties of thin films of the insulating perovskite PrBa2Cu3_yNbyO7_Z (PrBCNO for y=l). This material is a promising candidate for applications requiring high quality epitaxial insulating layers in YBa2Cu3O7-y thin film circuits: PrBCNO is nearly tetragonal with <2% lattice mismatch to YBCO thus allowing the possibility of epitaxial multilayer growth. Using pulsed laser deposition, we have grown both PrBCNO single films and PrBCNO-YBCO multi-layers; growth conditions typical for YBCO result in highly oriented c-axis PrBCNO films and multi-layers on a variety of (001) substrates. Preliminary measurements show a PrBCNO resistivity > 105 Ω-cm and an optical index of refraction of 2.25 at room temperature for y=l. © 1991 IEEE