Influence of Ag substrate surface condition on surface morphology of YBCO film

YBCO films were grown on polycrystalline Ag substrates by a metal-organic decomposition (MOD) method using Trifluoroacetate Salt (TFA). The surface defects of the Ag substrates, such as rolling stripe and crystal boundary, were found to have a detrimental effect on the crystal orientation and surface morphology of YBCO films. The surface of YBCO films deposited on Ag substrate annealed in vacuum has many holes and stripes, which are parallel to the rolling stripe on Ag substrates. At the crystal boundary grooves on Ag substrates annealed in Ar environment, the film compositions are not superconducting phases but oxide phases of Cu-O and Ba-Cu-O. To eliminate the rolling stripe and grooves on the Ag surface, we used cold rolling polished Ag as substrates. The film grown on cold rolling polished Ag substrates has a smooth surface and good connectivity of grains without parallel stripes and grooves. The films composition is also uniformity..