Nuclear quantum effects in structural and elastic properties of cubic silicon carbide

Abstract

Silicon carbide, a semiconducting material, has gained importance in the fields of ceramics, electronics, and renewable energy due to its remarkable hardness and resistance. In this study, we delve into the impact of nuclear quantum motion, or vibrational mode quantization, on the structural and elastic properties of 3C-SiC. This aspect, elusive in conventional {\it ab-initio} calculations, is explored through path-integral molecular dynamics (PIMD) simulations using an efficient tight-binding (TB) Hamiltonian. This investigation spans a wide range of temperatures and pressures, including tensile stress, adeptly addressing the quantization and anharmonicity inherent in solid-state vibrational modes. The accuracy of the TB model has been checked by comparison with density-functional-theory calculations at zero temperature. The magnitude of quantum effects is assessed by comparing PIMD outcomes with results obtained from classical molecular dynamics simulations. Our investigation uncovers notable reductions of 5%, 10%, and 4% in the elastic constants $C_{11}$, $C_{12}$, and $C_{44}$, respectively, attributed to atomic zero-point oscillations. Consequently, the bulk modulus and Poisson's ratio of 3C-SiC exhibit reduced values by 7% and 5% at low temperature. The persistence of these quantum effects in the material's structural and elastic attributes beyond room temperature underscores the necessity of incorporating nuclear quantum motion for an accurate description of these fundamental properties of SiC.

17 pages, 10 figures, 3 tables

References in corpus (23)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• High-accuracy first-principles determination of the structural, vibrational and thermodynamical properties of diamond, graphite, and derivatives
• Excitonic effects in the optical properties of SiC sheet and nanotubes
• Simulation and understanding of quantum crystals
• Bottom-up growth of monolayer honeycomb SiC
• Phase diagram of silicon from atomistic simulations
• Pressure Dependence of Born Effective Charges, Dielectric Constant and Lattice Dynamics in SiC
• A path-integral molecular dynamics simulation of diamond
• Kinetic energy of protons in ice Ih and water: a path integral study
• Quantum effects in graphene monolayers: Path-integral simulations
• Path-integral molecular dynamics simulation of 3C-SiC
• Hydrogen and muonium in diamond: A path-integral molecular dynamics simulation
• Thermal evolution of silicon carbide electronic bands
• Isotope effects on the lattice parameter of cubic SiC
• Cubic silicon carbide under tensile pressure: Spinodal instability
• Quantum effects in two-dimensional silicon carbide
• Nuclear quantum effects in graphane
• Nuclear quantum effects in graphene bilayers
• Quantum effects in structural and elastic properties of graphite: Path-integral simulations
• Isotopic effects in structural properties of graphene

Cited by in corpus (4)

• Pressure-Induced Mechanical Instabilities in Cubic SiC: Structural and Electronic Properties
• Quantum nuclear motion in silicene: Assessing structural and vibrational properties through path-integral simulations
• Elastic properties of silicene: Spinodal instabilities
• Elastic properties of cubic silicon carbide with Si vacancies