Thermal conductivity from approach-to-equilibrium molecular dynamics

Lampin, E.; Palla, Pier Luca; Francioso, Pierre-Arnaud; Cleri, Fabrizio

doi:10.1063/1.4815945

Cited by 105 publications

(107 citation statements)

References 22 publications

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“…This expression is fitted to the temperature gradient obtained from the simulations to determine κ. More details on the methodology can be found elsewhere [10,25,36]. …”

Section: A Aemd Simulationsmentioning

confidence: 99%

Thermal boundary resistance at Si/Ge interfaces determined by approach-to-equilibrium molecular dynamics simulations

Hahn¹,

Puligheddu²,

Colombo³

2015

Phys. Rev. B

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The thermal boundary resistance of Si/Ge interfaces has been determined using approach-to-equilibrium molecular dynamics simulations. Assuming a reciprocal linear dependence of the thermal boundary resistance, a length-independent bulk thermal boundary resistance could be extracted from the calculation resulting in a value of 3.76 × 10−9 m2 K/W for a sharp Si/Ge interface and thermal transport from Si to Ge. Introducing an interface with finite thickness of 0.5 nm consisting of a SiGe alloy, the bulk thermal resistance slightly decreases compared to the sharp Si/Ge interface. Further growth of the boundary leads to an increase in the bulk thermal boundary resistance. When the heat flow is inverted (Ge to Si), the thermal boundary resistance is found to be higher. From the differences in the thermal boundary resistance for different heat flow direction, a rectification factor of the Si/Ge interface can be determined and is found to significantly decrease when the sharp interface is moderated by introduction of a SiGe alloy in the boundary layer

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“…This expression is fitted to the temperature gradient obtained from the simulations to determine κ. More details on the methodology can be found elsewhere [10,25,36]. …”

Section: A Aemd Simulationsmentioning

confidence: 99%

Thermal boundary resistance at Si/Ge interfaces determined by approach-to-equilibrium molecular dynamics simulations

Hahn¹,

Puligheddu²,

Colombo³

2015

Phys. Rev. B

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“…[9,21,22] For the simulations of the present study, using the two fitting procedures gives results as shown in Fig. 8.…”

Section: Extrapolating the Bulk Thermal Conductivitymentioning

confidence: 99%

“…In a different, time-dependent approach, temperature transients can also be used to study the thermal response. [6,7] Recently, [8,9] we have shown that when a simulated temperature pulse establishes a step-difference temperature profile in a material, the transient to the equilibrium temperature is exponential, making it easy to extract a typical decay time of the thermal pulse. Using the heat equation, the thermal conductivity can be obtained from this decay time.…”

Section: Introductionmentioning

confidence: 99%

“…The advantage of this method, which we called "approach-to-equilibrium molecular dynamics", or AEMD, is that time transients occur faster, compared to both the attainment of a stationary regime of thermal conduction across a spatial gradient, as in the "direct" method, and to the numerical convergence required for the Green-Kubo relation in the EMD method. Therefore, much larger system sizes can be studied with AEMD, containing up to 4.5 millions atoms [9], and with length L Z as long as 0.1 mm for a graphene two-dimensional supercell [10].…”

Section: Introductionmentioning

confidence: 99%

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Length dependence of thermal conductivity by approach-to-equilibrium molecular dynamics

et al. 2016

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The length dependence of the thermal conductivity over more than two decades is systematically studied for a range of materials, interatomic potentials and temperatures, by the atomistic approach-to-equilibrium molecular dynamics method (AEMD). By comparing the values of conductivity obtained for a given supercell length and maximum phonon mean-free-path (MFP), we find that such values are strongly correlated, demonstrating that the AEMD calculation with a supercell of finite length, actually probes the thermal conductivity corresponding to a maximum phonon MFP. As a consequence, the less pronounced length dependence usually observed for poorer thermal conductors, such as amorphous silica, is physically justified by their shorter average phonon MFP. Finally, we compare different analytical extrapolations of the conductivity to infinite length, and demonstrate that the frequently used Matthiessen rule is not applicable in AEMD. An alternative extrapolation more suitable for transient-time, finite-supercell simulations is derived. This approximation scheme can also be used to classify the quality of different interatomic potential models with respect to their capability of predicting the experimental thermal conductivity. * evelyne.lampin@univ-lille1.fr

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“…In this work we offer some insight on this problem by performing unbiased (i.e., with no a priori guess) AEMD simulations [25,26] on pristine graphene monolayers with L z up to a size of 0.1 mm. Our goal is to ultimately state whether the claimed κ ∼ log L z divergence is indeed observed by a direct numerical estimate and, if so, whether this behavior drives to a divergent thermal conductivity for arbitrarily long samples.…”

mentioning

confidence: 99%

Intrinsic thermal conductivity in monolayer graphene is ultimately upper limited: A direct estimation by atomistic simulations

2015

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In the sample size domain so far explored, the thermal conductivity of graphene shows an intriguing dependence on the sample length Lz along the heat flux direction. An extrapolated infinite value for such a thermal conductivity is sometimes suggested for infinite samples, while other investigations predict anyway an upper limit for it. We address this issue by avoiding any guess or approximation on the underlying microscopic heat transport mechanisms; we rather perform direct atomistic simulations aimed at estimating thermal conductivity in samples with increasing size up to the unprecedented value of Lz=0.1 mm. Our results provide evidence that thermal conductivity in graphene is definitely upper limited in samples long enough to allow a diffusive transport regime for both single and collective phonon excitations

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Thermal conductivity from approach-to-equilibrium molecular dynamics

Cited by 105 publications

References 22 publications

Thermal boundary resistance at Si/Ge interfaces determined by approach-to-equilibrium molecular dynamics simulations

Thermal boundary resistance at Si/Ge interfaces determined by approach-to-equilibrium molecular dynamics simulations

Length dependence of thermal conductivity by approach-to-equilibrium molecular dynamics

Intrinsic thermal conductivity in monolayer graphene is ultimately upper limited: A direct estimation by atomistic simulations

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