Topographic and electronic structure of cleaved SrTiO{sub 3}(001) surfaces
- Department of Materials Science and Engineering, Carnegie Mellon University, Robert Engineering Hall, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States)
- Department of Physics, Carnegie Mellon University, Wean Hall, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States)
The topographic and electronic structure of cleaved SrTiO{sub 3}(001) surfaces were studied, employing samples that either had or had not been coated with Ti on their outer surfaces prior to fracture. In both cases, SrO- and TiO{sub 2}-terminated terraces were present on the cleavage surface, enabling in situ studies on either termination. However, the samples coated with Ti prior to fracture were found to yield a rougher morphology on TiO{sub 2}-terminated terraces as well as a higher density of oxygen vacancies during an annealing (outgassing) step following the coating. The higher density of oxygen vacancies in the bulk of the Ti-coated samples also provides higher conductivity, which, in turn, improves a sensitivity of the spectroscopy and reduces the effect of tip-induced band bending. Nonetheless, similar spectral features, unique to each termination, were observed for samples both with and without the Ti coating. Notably, with moderate-temperature annealing following fracture, a strong discrete peak in the conductance spectra, arising from oxygen vacancies, was observed on the SrO-terminated terraces. This peak appears at slightly different voltages for coated and uncoated samples, signifying a possible effect of tip-induced band bending.
- OSTI ID:
- 22392173
- Journal Information:
- Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 33, Issue 3; Other Information: (c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
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