Ultramicroanalysis of Y-Ba-Cu-O ceramics with the atom-probe microscope

Abstract
We demonstrate that the atom-probe microscope has a unique capability for micro-mass-analyzing the Y-Ba-Cu-O superconducting ceramics. The analysis indicates that the ceramics contain extremely Cu-rich and Ba-rich regions. Even in a Y-Ba-Cu-O region with an appropriate composition the local composition varies noticeably over a range of 2030 Å, which is a few times the perovskite lattice parameter.