Abstract
The influence of target processing on properties of deposited NBCO films, including superconductivity, epitaxial structure, and surface morphology has been systematically investigated between a large Nd123 single crystal and slightly Ba-rich Nd/sub 1-x/Ba/sub 2+x/Cu/sub 3/O/sub 7-/spl delta// (x=0.00, 0.03, 0.05, and 0.10) sintered ceramic targets. The films with excellent superconductivity and good crystallinity were grown on SrTiO/sub 3/ [100], LaAlO/sub 3/ [100], and NdGaO/sub 3/ [110] substrates by pulsed laser deposition (PLD). At optimized deposition conditions, T/sub c0/ of 90-94 K is routinely achieved. The critical current density J/sub c/ is >3/spl times/10/sup 6/ A/cm/sup 2/ at 77 K. The films deposited from sintered targets exhibit a typical droplet density of 10/sup 6/-10/sup 7//cm/sup 2/ on the film surface. However, the films deposited from the single crystal target show smooth nearly droplet-free surface morphology. Our results indicate that single crystal targets are more suitable for the growth of smooth high-T/sub c/ superconducting films by PLD.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have