Continuous deposition of ex situ YBCO precursor films on rolling-assisted biaxially textured substrates by electron beam evaporation

A reel-to-reel electron beam evaporation system has been developed to conti nuously deposit Y-BaF2-Cu precursor for ex situ YBa2Cu3O7-x (YBCO) processe d films, The quality of a YBCO film on biaxially textured, oxide buffered, Ni tape strongly depends on the condition of the precursor deposit. For con tinuous precursor deposition, a uniform cation stoichiometry (i.e., Y:Ba:Cu = 1:2:3) over the entire length of precursor film is essential. Rutherford backscattering spectrometry studies indicated that the partial pressure of water vapor during the deposition has a significant effect on cation depos ition rates and the oxygen content in the precursor film. The oxygen conten t of the precursor is increased and the precursor stability upon exposure t o air is improved by introduction of water vapor during precursor depositio n. High quality precursor films with a thickness of 300 nm have been deposi ted on lengths of rolling-assisted, biaxially textured substrates in the re el-to-reel electron beam evaporation system. In this paper, long length pre cursor deposition processing will be discussed. Properties of some post-ann ealed YBCO films will also be presented. (C) 2001 Elsevier Science B.V. All rights reserved.