Electronic structure of a grain-boundary model in SrTiO{sub 3}
- Department of Physics, University of Missouri--Kansas City, Kansas City, Missouri 64110 (United States)
- Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
It is known that grain boundaries (GB{close_quote}s) in strontium titanate (SrTiO{sub 3}) play an important and often a controlling role in determining the material{close_quote}s electrical properties. To understand how their electronic structures are related to the GB structures, we have examined two structure models of the {Sigma}5 GB in SrTiO{sub 3} obtained by first-principles pseudopotential total energy calculations. The electronic structure of bulk crystal and the relaxed GB models are then studied by using the orthogonalized linear combination of atomic orbitals method. Results are presented for the ground-state structural properties and band structure of bulk SrTiO{sub 3}, the total density of states (DOS), the atom and orbital-resolved partial DOS, effective charges, bond order, charge-density distribution, and near-edge structure of electron energy-loss spectroscopy. It is shown that the GB structures have smaller values of fundamental band gaps, effective charges, and bond orders relative to bulk SrTiO{sub 3}. There are no GB-induced electronic states within or at the edge of the fundamental band gap. The 100-atom GB model with buckled Sr columns in the GB core is found to be a more likely model. It is also shown that the electron charge distribution across the GB line in SrTiO{sub 3} is almost balanced. {copyright} {ital 1999} {ital The American Physical Society}
- OSTI ID:
- 355449
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 4 Vol. 60; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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