Presentation Information
[22p-C501-2]Analysis of coherent phonon transport in Graphite with FeCl3 intercalation
〇Yijia WU1, Masato Ohnishi1,2, Chandra Harsh1, Jie Sun1,2, Junichiro Shiomi1,2 (1.Dept. of Mech. Eng.,Tokyo Univ., 2.Inst. of Eng. Innovation,Tokyo Univ.)
Keywords:
coherent heat transfer,tunable thermal property,Graphite Intercalation Compound
In this work, non-equilibrium molecular dynamics simulations were performed on FeCl3-graphite intercalation compounds with various nanostructures, including different stages (i.e., number of graphene layers between two intercalated FeCl3 layers), thickness and filling factor. We found that the cross-plane thermal conductivity increased with an increase in stage in a manner consistent with incoherent phonon boundary scattering from FeCl3 layers. However, at low stage, the decrease of cross-plane thermal conductivity as long-wavelength coherent phonon modes were expected to play a dominant role in the thermal transport, and the thermal conductivity values reached a saturated value of 0.3 W/m·K at stage5. Based on molecular dynamics with spectral energy density (SED) analysis, we revealed that thermal conductivity decreases mainly due to wave interference effect, namely, zone-folding effect induced by intercalated compounds. Meanwhile, intercalation of FeCl3 significantly increased the phonon group velocity owing to the extra electrostatic and dispersion interaction induced by FeCl3.The increased group velocity along the c-axis together with the suppressed phonon lifetime resulted in the nonmonotonic change of cross-plane thermal conductivity of GIC with different periodic distances. The present work provides valuable insights into modulating the thermal properties of graphite by tuning phonon wave nature at room temperature with intercalated layered materials.