ARXPS, SEM, and SAM studies of highly textured YBa2Cu 3Ox films

The electric conduction in the new cuprate superconductors suffers from intragrain and intergrain weak links. In transition metal oxides weak links show up in a specific chemistry, which can be measured by X-ray photoelectron spectroscopy and by Auger electron spectroscopy. To measure a defective local chemistry, the chemical signature of the reaction cinder has to be identified and the chemical signature of the perfect crystal has to be established. For highly textured cuprate films this has been done successfully, yielding the signature of the reaction cinder, e.g. BaO₂ or graphite, the signature of the interface reactions, e.g. Ba-aluminate on Al₂O₃ or Cu diffusion into MgO, and the signature of c-axis surfaces being a BaO_x layer on YBa₂Cu₃O_x, which results in a 1-nm-thick insulating layer