相关论文: Rigid Unit Modes in $sp$-$sp^2$ Hybridized Carbon …
We present a simple analytical approach to study anharmonic effects in single layer, bilayer, and multilayer graphene. The coupling between in plane and out of plane modes leads to negative Gr\"uneisen coefficients and negative thermal…
Graphene and its derivatives distinguish themselves for their large negative thermal expansion even at temperatures as high as 1000K. The linear thermal expansion coefficients (LTEC) of two-dimensional honeycomb structured pure graphene and…
We present a comprehensive investigation of the low-temperature heat capacity of thermally reduced graphene oxide (trGO) as a function of compaction pressure and annealing temperature. Graphene oxide was synthesized using a modified Hummers…
We have investigated the anisotropic thermal expansion of graphite using ab-initio calculation of lattice dynamics and anharmonicity of the phonons, which reveal that the negative thermal expansion (NTE) in the a-b plane below 600 K and…
Based on first-principles calculation using density functional theory, we study the vibrational properties and thermal expansion of mono-atomic two-dimensional honeycomb lattices: graphene, silicene, germanene and blue phosphorene. We focus…
Proceeding from the model of a two-dimensional elastic continuum, we describe the characteristic features of thermal expansion of graphene using an approach that goes beyond the quasi-harmonic approximation. The negative value of the…
We have calculated the implicit shift for various modes of frequency in a pure graphene sheet. Thermal expansion and Gr\"uneisen parameter which are required for implicit shift calculation have already been studied and reported. For this…
Graphene and its derivatives including hexagonal BN are notorious for their large negative thermal expansion over a wide range of temperature which is quite unusual. We attempt to analyze this unusual behavior on the basis of character of…
Anomalous thermal expansion behaviour of several open frame-work compounds has been extensively investigated using the techniques of inelastic neutron scattering and lattice dynamics. These compounds involve increasing level of structural…
Using non-equilibrium molecular dynamics method(NEMD), we have found that the thermal conductivity of multilayer graphene nanoribbons monotonously decreases with the increase of the number of layers, such behavior can be attributed to the…
We present a phenomenological force-constant model developed for the description of lattice dynamics of sp2 hybridized carbon networks. Within this model approach, we introduce a new set of parameters to calculate the phonon dispersion of…
The mechanical properties of two-dimensional materials are important for a wide range of applications including composite and van der Waals-materials, flexible electronics and superconductivity. Several aspects are highly debated in the…
We report a hierarchical first-principles investigation on the entangled effects of lattice dimensionality and bond characteristics in the lattice dynamics of silicene and germanene. It is found that bond bending (stretching) negatively…
We reveal that phononic thermal transport in graphene is not immune to grain boundaries (GBs) aligned along the direction of the temperature gradient. Non-equilibrium molecular dynamics simulations uncover a large reduction in the phononic…
Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with…
The effect of grain boundary (GB) structure, size and shape on thermal conductivity of polycrystalline graphene is studied in the framework of the deformation potential approach. Precise analytical expressions for the phonon mean free path…
Through the integration of the power spectral density, we obtain temperature profiles of both multi-segment harmonic and anharmonic systems, showing the presence of an anomalous negative temperature gradient inside the interfacial segment.…
Ab initio density functional theory has been used to analyze flexural modes, elastic constants, and atomic corrugations on single and bi-layer graphene. Frequencies of flexural modes are sensitive to compressive stress; its variation under…
We present systematic thermal conductivity measurements of suspended thin graphite ribbons, 234-527 nm thick, using a four-probe 3-omega method. Unlike recent reports of phonon hydrodynamics and exceptionally high thermal conductivity in…
We delineated the role of thermally excited ripples on thermal expansion properties of 2D honeycomb materials (free-standing graphene, 2D h-BN, and ML-MoS2), by explicitly carrying out three-dimensional (3D) and two-dimensional (2D)…