Superconducting NdBa2Cu3O7-delta thin films grown on bare (1(1)over-bar02) sapphire by pulsed laser deposition

Abstract

Superconducting NdBa2Cu3O7-delta (NBCO) thin films with T-c=89 K have been. successfully grown on bare (1 (1) over bar 02) sapphire substrates by pulsed laser deposition (PLD). The X-ray diffraction results show that the as-grown NBCO films are all c-axis oriented with no observable second phase. The c-axis parameter decreases monotonically with increasing the deposition temperature (T-s), suggesting that the corresponding degradation of T-c for T-s>790degreesC might not originate from oxygen deficiency. It is conceived that the film-substrate reaction that occurring at the interface may cause Ba-deficiency and hence enhance Nd-Ba antisite substitutions.