Growth and properties of NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///PrBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// quasi-homostructures for the fabrication of electronic devices

摘要

We report on well-characterized c-axis quasi-homoepitaxial multilayers made of NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (NBCO) and PrBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (PBCO) films with very smooth surface morphology and high crystallinity, grown on SrTiO/sub 3/ substrates by pulsed laser deposition (PLD). X-ray diffraction (XRD), transmission electron microscopy (RBS) and Rutherford backscattering spectrometry (RBS) analyses provide evidence of long-range crystalline perfection, and a well-equilibrated and relaxed crystal. Furthermore, high quality junctions were fabricated from c-axis-oriented NBCO/PBCO/NBCO multilayers. The current-voltage characteristics (CVC) exhibit supercurrent and quasi-particle tunneling that is commonly observed for superconductor-insulator-superconductor (SIS) junctions. Our results show the importance of using barrier layer materials of PBCO sandwiched between NBCO electrodes for the fabrication of electronic devices.