Most of the analytical techniques used in thin film research are insensitive to oxygen, and many are prone to thickness-dependent systematic errors. Electron Probe Microanalysis (EPMA) can give accurate analyses of thin films if sufficiently low accelerating voltages are used. We have used the technique to study whether fine stoichiometric changes are responsible for the quality differences that are observed in YBa2Cu3O7−x thin films produced at different substrate temperatures.
