Characterization of liquid phase epitaxy grown YBa/sub 2/Cu/sub 3/O/sub 7-x/ thick films as superconductive substrates

The liquid phase epitaxy (LPE) grown YBa/sub 2/Cu/sub 3/O/sub x/ (YBCO) thick films are characterized as a superconductive substrate in comparison with bulk YBCO single crystal substrates. We have focused on the study of the chemical treatments improving the [001] YBCO surface which is mechanically polished. The reaction of the YBCO surface with the HCl/absolute methanol solution is effective for removing damaged remnants on the surface without roughening. Resulting surfaces are precisely examined by observations of atomic force microscopy. The topographical image and its line profile have confirmed that [001] YBCO surfaces are terminated by a unique atomic layer. The chemical stability is also examined under the conditions that additional depositions are followed to form a multilayer structure for devices.