a-axis oriented YBa2Cu3O7−x thin films on Si with CeO2 buffer layers

Abstract
We have grown a‐axis oriented YBa2Cu3O7−x (YBCO) thin films on Si(100) substrates with (110) oriented insulating buffer layers of cerium dioxide (CeO2) using the pulsed laser deposition technique. The films are highly oriented and textured as determined by θ–2θ x‐ray diffraction, x‐ray pole‐figure scan, scanning electron microscopy, Rutherford backscattering spectroscopy, and ion channeling. No diffusion at the interface has been found at growth temperatures up to 760 °C, indicating the CeO2 is a chemically stable and structurally compatible intermediate material for the growth of YBCO on Si. A zero resistance superconducting transition temperature of 87 K and a critical‐current density (Jc) of 1.5×105 A/cm2 at 75 K have been measured; Jc obtained represents the highest value for the a‐axis oriented YBCO films.