About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
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Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
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| Presentation Title |
DFT Quantification of Volumetric and Interfacial Energies Involved in Epitaxial Stabilization of Columbite SnO2 |
| Author(s) |
Nahyun Kim, Sara A. Majetich, Paul A. Salvador |
| On-Site Speaker (Planned) |
Nahyun Kim |
| Abstract Scope |
Density functional theory was used to quantify the volumetric formation, the volumetric strain, and the film-substrate interface energies relevant to polymorph selection during epitaxial growth of SnO2, with the interfacial terms being the primary research challenge. These energies were computed for rutile (r) and columbite (c) SnO2 crystallizing on a c-SnO2 substrate, using orientation relationships and coherent interfaces suggested from prior experimental observations (the close-packed planes and directions are aligned). The (101)r||(010)c interface, which has consistent cation packing across the interface (and low misfit strains), has a low interface energy of approximately 0.1 J/m2, which results in the preferred growth of the bulk-stable r-SnO2. Conversely, interfaces where r-SnO2 has inconsistent cation packing across the interface have interfacial energies that are about 1 J/m2, which then support persistent nucleation of the metastable c-SnO2. We will discuss the relative importance of each of the computed energies for epitaxial stabilization of metastable phases. |