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| Main Authors: | , , , , , |
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| Format: | Preprint |
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2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2406.19155 |
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| _version_ | 1866910504398618624 |
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| author | Poulos, Markos Papagelis, Konstantinos Koukaras, Emmenuel N. Kalosakas, George Fugallo, Giorgia Termentzidis, Konstantinos |
| author_facet | Poulos, Markos Papagelis, Konstantinos Koukaras, Emmenuel N. Kalosakas, George Fugallo, Giorgia Termentzidis, Konstantinos |
| contents | In this work, we have studied the phonon properties of multi-layered graphene with the use of Molecular Dynamics (MD) simulations and the k-space Autocorrelation Sequence (k-VACS) method. We calculate the phonon dispersion curves, densities of states and lifetimes $τ$ of few-layered graphene of 1-5 layers and graphite. $Γ$-point phonon energies and lifetimes are investigated for different temperatures ranging from 80 K to 1000 K. The study focuses on the impact of the interlayer interaction and temperature on the energies and lifetimes of the $Γ$-point phonons, as well as the type of interlayer potential used. For the later we used the Kolmogorov-Crespi (KC) and the Lennard-Jones (LJ) potentials. We have found that the number of layers $N$ has little effect on the intra-layer (ZO and G) mode energies and greater effect on the inter-layer (Layer Shearing and Layer Breathing) modes, while $τ$ is generally affected by $N$ for all modes, except for the Layer Shear mode. The trend of $N$ on the lifetimes was also found to independent of the type of potential used. For the Raman-active G phonon, our calculations show that the lifetime increase with $N$ and that this increase is directly connected to the strength of the interlayer coupling and how this is modelled. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2406_19155 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Temperature Dependence of Phonon Energies and Lifetimes in Single- and Few-layered Graphene Poulos, Markos Papagelis, Konstantinos Koukaras, Emmenuel N. Kalosakas, George Fugallo, Giorgia Termentzidis, Konstantinos Materials Science In this work, we have studied the phonon properties of multi-layered graphene with the use of Molecular Dynamics (MD) simulations and the k-space Autocorrelation Sequence (k-VACS) method. We calculate the phonon dispersion curves, densities of states and lifetimes $τ$ of few-layered graphene of 1-5 layers and graphite. $Γ$-point phonon energies and lifetimes are investigated for different temperatures ranging from 80 K to 1000 K. The study focuses on the impact of the interlayer interaction and temperature on the energies and lifetimes of the $Γ$-point phonons, as well as the type of interlayer potential used. For the later we used the Kolmogorov-Crespi (KC) and the Lennard-Jones (LJ) potentials. We have found that the number of layers $N$ has little effect on the intra-layer (ZO and G) mode energies and greater effect on the inter-layer (Layer Shearing and Layer Breathing) modes, while $τ$ is generally affected by $N$ for all modes, except for the Layer Shear mode. The trend of $N$ on the lifetimes was also found to independent of the type of potential used. For the Raman-active G phonon, our calculations show that the lifetime increase with $N$ and that this increase is directly connected to the strength of the interlayer coupling and how this is modelled. |
| title | Temperature Dependence of Phonon Energies and Lifetimes in Single- and Few-layered Graphene |
| topic | Materials Science |
| url | https://arxiv.org/abs/2406.19155 |