In-situ annealing effect of sputter-deposited Nd1Ba2Cu3O7-delta thin films

The in-situ annealing of NdBa2Cu3O7-delta (NBCO) thin films was conducted s o as to find means for improving chin film quality. NBCO thin films were pr epared on a MgO (100) substrate by single target dc-magnetron sputtering. A fter deposition, while cooling to room temperature, films were annealed at 600-350 degrees C for 0.5-80 h under 300 Torr O-2 gas atmosphere in the dep osition chamber. Superconducting properties as well as features such as res istivity in the normal state and surface roughness were improved by optimiz ing annealing parameters. Highly c-axis oriented thin films having zero res istance temperature (T-c = 94.3 K) were obtained by in situ annealing treat ment. Thin films with critical current density (J(c)) of 1x10(6) A/cm at 77 K, and mean surface roughness of 5.5 nm were obtained under optimal anneal ing conditions. (C) 1999 Elsevier Science S.A. All rights reserved.