X-RAY PHOTOEMISSION SPECTROSCOPY OF LA0.67CA0.33MNO3 FILMS

We have performed X-ray photoemission spectroscopy (XPS) on thin films of (001) and (200) oriented La0.67Ca0.33MnO3 grown on (100) and (110) SrTiO3 substrates by off-axis sputtering. The films were examined by XPS without exposing them to air. We have compared the core levels and the valence spectra between the two different orientations, as well a s after the effects of air exposure and annealing in UHV. We find that the surfaces are very stable against exposure to air. Comparing the m easured intensity ratios to a model for the uniform termination of the film shows the terminating layer to be MnO2 for both the (001) and (2 00) oriented La0.67Ca0.33MnO3 films.