Photoemission measurements on SrRuO_3/SrTiO3 films grown by in-situ pulsed laser deposition
Abstract
The electronic structures of SrRuO3 thin films on the SrTiO3 substrate grown by in situ Pulsed Laser Deposition are investigated using ultraviolet and x ray photoemission spectroscopy. It is shown that the valence spectra of the as-grown films are different from those of polycrystals prepared by scraping: the former spectrum shows stronger coherent peak than the latter one. O 1s and Sr 3d core-level XPS reveal that polycrystals have an additional core level structure located at the higher binding energy than the case of metallic SrRuO_3. This indicates the presence of more insulating chemical states in case of polycrystals, which probably reside in the grain boundary and are exposed by scraping. In constrast, the core level spectra of in-situ grown films are mostly composed of metallic chemical state. It is concluded that the very incoherent UPS spectrum of polycrystal sample is in large part due to the presence of defect chemical states which show more insulating behavior than metallic SrRuO_3.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARS24012K