Fabrication and characterization of high quality NdBa/sub 2/Cu/sub 3/O/sub 7-δ//Sr/sub 2/AlTaO/sub 6//NdBa/sub 2/Cu/sub 3/O/sub 7-δ/ and NdBa/sub 2/Cu/sub 3/O/sub 7-δ//Sr/sub 2/AlNbO/sub 6//NdBa/sub 2/Cu/sub 3/O/sub 7-δ/ multilayers

Abstract

High quality epitaxial Sr/sub 2/AlTaO/sub 6/ (SAT) and Sr/sub 2/AlNbO/sub 6/ (SAN) insulator films as well as the related trilayers of NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (NBCO)/SAT/NBCO and NBCO/SAN/NBCO have been successfully grown on SrTiO/sub 3/ [100], LaAlO/sub 3/ [100], and YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//(YBCO) [001] single crystal substrates by pulsed laser deposition (PLD). The top and bottom NBCO layers have a T/sub c/0 of 87-90 K and J/sub c/>10/sup 6/ A/cm/sup 2/ at 77 K, measured by four-probe and dc magnetization methods. X-ray diffraction and transmission electron microscopy analyses reveal that the deposited trilayers have an all-epitaxial structure and abrupt interface without interdiffusion. We also measured the dielectric properties of SAT layers using the patterned structures on YBCO [001] single crystal substrates. Our results show that SAT and SAN can be used as insulator layers on YBCO single crystal substrate in high-T/sub c/ superconducting multilayer processing including NBCO films.