Density Functional Theory Study of sigma9 {122} Grain Boundaries in Silicon and Silicon Carbide-3C
Abstract
In this report, we perform a first-principles density functional theory (DFT) study of the interfacial energies and electronic structure of the sigma9 {122} tilt grain boundary in silicon carbide (SiC)-3C and Si. In SiC-3C, there are three unique reconstructions of this grain boundary: nonpolar, polar C-rich, and polar Si-rich. DFT calculations determined the interfacial energy for the sigma9 {122} silicon, sigma9 {122} SiC-3C nonpolar, and sigma9 {122} SiC-3C polar interfaces are 0.1821, 1.346, and 1.336 J/m2, respectively, indicating the polar interface is more stable in SiC-3C. However, due to periodic boundary conditions, the interfacial energy calculated for the polar interface is an average of the two unique polar Si-rich and C-rich interfaces, whereas the nonpolar interface is symmetric within the supercell. In addition, a detailed analysis of the electronic structure including the electron density difference, Mulliken charge transfer, and atom-resolved partial density of states within the grain boundary region was performed to determine how electron redistribution and interfacial reconstruction affects local chemical reactivity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2020
- Accession Number
- AD1109821
Entities
People
- Jennifer Synowczynski-dunn
- Matthew Guziewski
- Shawn P Coleman
Organizations
- United States Army Research Laboratory