Electronic thermal properties of twisted bigraphene

Electronic heat transfer in disordered twisted bigraphene was investigated taking into account the disorder that arises when the layers rotate relative to each other and the formation of local areas of short-range order various types in the structure. Analytical expressions for the electron heat capacity and thermal conductivity are obtained and analyzed depending on the temperature, rotation angle, concentration and point of attachment of foreign atoms relative to the surface of the material. It is shown that the deviation from the linear temperature dependence of the electronic thermal properties is due to the dependence of the relaxation time of electrons multiply scattered in the short-range order regions on the temperature and rotation angle of the graphene layers. At large rotation angles, the electron heat capacity and thermal conductivity are ~T, regardless of the type of structural defects and the concentration of foreign atoms. Changes in the temperature dependence of the electronic thermal properties are observed when foreign atoms are localized in the first coordination sphere and small rotation angles (up to 15°). Accounting for the scattering of electrons by short-range ordered complexes of this type leads to a nonlinear temperature dependence of the electron thermal conductivity ( ~ T^1.5), which corresponds to the experimental data. In this case, the value of heat capacity and thermal conductivity is determined only by the rotation angle between the layers, which decreases with its growth. The value of the electronic heat capacity and thermal conductivity is determined by the angle of rotation and decreases with its growth. The maximum electronic contribution up to 10% of the total thermal conductivity can be observed at small angles and localization of foreign atoms in the first coordination sphere on the surface of twisted bigraphene.

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