<p>I want delay publication of my dissertation until April 30 2013. Thanks.</p> / <p>Strontium titanate (SrTiO<sub>3</sub>) has a wide range of applications in the electronic industry and attracts growing world-widely interest recently because of novel discoveries at its surfaces, interfaces and with selected dopants. The understanding of some of the structural properties of SrTiO<sub>3</sub> and its optical properties have been lagging due to limited characterization techniques available to study single monolayers and dopants in this material.</p> <p>In the present thesis, pure SrTiO<sub>3</sub> single crystals with (2x1) and c(4x2) surface patterns were synthesized and samples (Pr, Al) doped SrTiO<sub>3</sub> were prepared through ion implantation. The atomic and electronic structures of these samples were investigated by various high-resolution imaging and spectroscopic techniques available in an aberration-corrected transmission electron microscope. Particularly, the direct imaging of individual light atoms and vacancies within a bulk material containing heavier elements was demonstrated for the first time via the STEM-annular dark-field (ADF)/annular bright-field (ABF) images. In addition, the first electron energy-loss spectroscopy (EELS) 2-dimensional maps of dopants located in a lattice were obtained. These results provided a solid foundation regarding the mechanism of red light emission in doped SrTiO<sub>3</sub>. More importantly, a new experimental approach allowing the effective extraction of weak EELS signals from low-dimensional defects was developed and successfully applied to understand the chemical state and coordination of Ti cations within a single monolayer on a reconstructured SrTiO<sub>3 </sub>surface and the local defect configurations of injected Pr<sup>+</sup> and Al<sup>+</sup> ions within SrTiO<sub>3</sub> single crystals.</p> / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/12518 |
| Date | 10 1900 |
| Creators | Zhu, Guozhen |
| Contributors | Botton, Gianluigi, Materials Science and Engineering |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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