THE EFFECTS OF BEATING AND ANNEALING PROCESSES ON THE SURFACE-MORPHOLOGY AND QUALITY OF DOUBLE-SIDED YBA2CU3O7-DELTA THIN-FILMS

A series of YBa2Cu3O7-delta (YBCO) double-sided thin films were prepar ed by pulsed-laser deposition (PLD) and measured by XRD, SEM, AFM, ele ctrical-transport and microwave surface resistance (R-s) measurements. The results showed that the surface morphology of the first side of t he film consisted of more troughs and big particles, while that of the second side of the film consisted of almost no troughs but small, bar -like oriented particles. The difference has been attributed to the he ating and annealing processes during deposition. The improved substrat e surface conditions for the deposition of the second side of the film led to better film quality in terms of the T-cO and R-s values. Our r esults implied that a pre-annealing process of the substrates and a pr oper post-annealing process of the films after deposition would improv e the film quality and reduce the difference between the two sides of the YBCO films fabricated by PLD. (C) 1998 Elsevier Science B.V.