Abstract
We investigate the mechanical properties of graphene-like hexagonal germanium carbide monolayers (g-GeC) using first-principles calculations based on density-functional theory. Compared to graphene, g-GeC is much softer, with 41% in-plane stiffness, 44%, 42% and 37% ultimate strengths in armchair, zigzag, and biaxial strains respectively, as well as smaller ultimate strains. However, g-GeC has a larger Poisson's ratio, 0.28, about 1.5 times that of graphene. We obtained the second, third, fourth, and fifth order elastic constants for a rigorous continuum description of the elastic response of g-GeC. The second order elastic constants, including in-plane stiffness, are predicted to monotonically increase with pressure while the Poisson's ratio monotonically decreases with increasing pressure. The sound velocity of a compressional wave has a minima at an in-plane pressure of -7 GPa while that of a shear wave monotonically with pressure.
| Original language | English |
|---|---|
| Pages (from-to) | 135-141 |
| Number of pages | 7 |
| Journal | Mechanics of Materials |
| Volume | 64 |
| DOIs | |
| State | Published - 2013 |
| Externally published | Yes |
Bibliographical note
Funding Information:The authors would like to acknowledge the generous financial support from the Defense Threat Reduction Agency (DTRA) Grant # BRBAA08-C-2–0130 and # HDTRA1–13-1–0025 , U.S. Nuclear Regulatory Commission Faculty Development Program Grant # NRC-38–08-950 and U.S. Department of Energy (DOE) Nuclear Energy University Program (NEUP) Grant # DE-NE0000325 .
Keywords
- 2D materials
- Density functional theory
- High order elastic constants
- Honeycomb structure
- Mechanical properties
- g-GeC
ASJC Scopus subject areas
- Instrumentation
- General Materials Science
- Mechanics of Materials