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Information × Registration Number 0223U000716, 0122U001482 , R & D reports Title Quasiparticle interaction with the nanostructure surfaces with various roughness’s value. popup.stage_title Head Niemchenko Konstantyn E., Доктор фізико-математичних наук Registration Date 19-01-2023 Organization V.N. Karazin Kharkiv National University popup.description2 In this work, the physical mechanisms of phonon scattering at the boundaries of the sample in the two-dimensional case and their influence on the thermal conductivity of the sample are investigated. An analytical model of thermal conductivity of two-dimensional phonon gas in two-dimensional samples of finite dimensions is proposed. The main goal of the work is to consider the physical mechanisms that ensure the transition from specular boundary conditions to fully diffusive ones. In particular, a model for effective consideration of roughness for the limiting cases of weak and absolute diffuse scattering is proposed and compared with existing models. The work investigates the stationary non-equilibrium state of the phonon system, which is provided only by the interaction of phonons with the lateral boundaries of the samples. As a result of solving the problem, a system of integral equations was obtained for the distribution functions of phonons incident and emitted by the lateral boundaries. This system can be solved both by an iterative method and approximately analytically. The obtained solutions describe the balance of heat flows, the temperature distribution in the sample and the dependence of the effective coefficient of thermal conductivity on the size of the sample. The proposed methods of taking into account successive phonon interactions with boundaries with arbitrary levels of roughness make it possible to determine the conditions of applicability for existing models of thermal conductivity of two- dimensional samples of finite dimensions.  Product Description popup.authors Ermakov Oleg E Vovk Ruslan V. Niemchenko Kostiantyn E. Rogova Svitlana Yurievna popup.nrat_date 2023-01-19 Close