hide
Free keywords:
-
Abstract:
The influence of a negative electric field on the near-surface composition of Y-Ba-Cu-O superconductors, which have initially lost oxygen due to exposure to vacuum and FIM imaging, is investigated using a wide-angle atom probe. Field electron emission of about 10−8 A for about 10 min, at 85 K, causes significant changes in composition which are interpreted to mean primarily that oxygen has diffused to the surface and desorbed, resulting in a more metallic surface. These changes are correlated with recently observed shifts in field ion- and field-electron energy spectra.
