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Information × Registration Number 0221U106780, 0121U111445 , R & D reports Title Quantum tunneling of vibrational excitations in thermal conductivity of crystalline and amorphous materials and composites popup.stage_title Head Kryvchikov Oleksandr I., Доктор фізико-математичних наук Registration Date 20-12-2021 Organization B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine popup.description2  Modernization and automation of set-up for isochoric thermal conductivity measurements have been completed. It was perfomed a successful measurement of thermal conductivity for reference samples to test high-pressure cell and also temperature dependence of thermal conductivity of amorphous glycerol was established; so new information due to quantum tunneling contribution to isochoric thermal conductivity both amorphous and crystalline glycerol was obtained. Some events were held to discuss and promote knowledges devotes “Thermal Conductivity of Solids” including section "Dynamics and thermal properties of disordered systems" during the All-Ukrainian Conference of Researchers (Lviv) and a series of lectures for graduate students at the B.Verkin ILTPE of NASU. The analysis of thermal conductivity data someone crystalline and amorphous substances such as polymers, skutterudites, glycerol, amorphous carbon materials, etc was carried out within the developed universal approach to the description of thermal conductivity of solids. It was shown that these data can be represented as sum of two contributions, quasiparticle and wave. Based on the comparative analysis of diffuson contributions to the thermal conductivity both crystalline and amorphous materials involving the experimental results of isobaric and isochoric thermal conductivities studies, the functional dependences of quantum tunneling contribution to thermal conductivity and activation energies have been calculated. It was carried out the analysis of temperature dependences of heat capacity someone crystalline, amorphous and nanostructured substances; also the reasons of appearence of so-called boson peak were discussed. The obtained results are important to identify the influence of structure features and to predict the thermophysical features for nanomaterials and composites. The obtained results were presented at international conferences and published in high-rated journals. Product Description popup.authors popup.nrat_date 2021-12-20 Close