THIN-FILM DEPOSITION AND INTERFACE CHARACTERIZATION OF YBCO ON LINBO3SUBSTRATES

High transition temperature superconducting YBa2CU3O7-x (YBCO) thin fi lms have been epitaxially grown on YZ-cut LiNbO3 (LNO) substrates by t he pulsed laser deposition technique. The interface between YBCO and L NO has been systematically investigated by scanning electron microscop y, atomic force microscopy, Auger electron spectroscopy, and x-ray pho toelectron spectroscopy. Off-stoichiometry LiNbOx phases are found to segregate on the substrate surface because of lithium and oxygen vacan cies formed during the high temperature YBCO growth. These submicromet er particles are observed along the Z-axis on the X-Z plane of LNO wit h height of similar to 30 nm above the LNO surface. This rough growth surface results in YBa2Cu3O7-x thin films grown on the LNO surface tha t have reduced J(c) and T-c, possibly limiting the use of YBCO/LNO het erostructures for surface acoustic wave (SAW) devices.