Thermal conductivity of nanostructures

Specific features of the heat transfer in nanostructures and methods of their investigation are discussed. Phonon heat conduction that is characteristic of semiconductors and insulators is considered. In nanostructures, the Fourier law is violated and the methods of classical theory of heat conduction are inapplicable. Analysis of the physics of heat-transfer processes has shown that the heat conduction of nanostructures depends on the shape and size of the sample, properties of its surface, and direction of the heat flow with respect to the nanostructure geometry. This fact has led to the development of radically new approaches to the determination of thermal conductivity of solids on the nano- and micrometer scales. Therefore, main attention is paid to the review of existing methods for finding thermal conductivity of nanostructures and the results of its theoretical and experimental determination. Various models of heat transfer in nanostructures are presented. The knowledge of statistical thermodynamics, kinetic theory, and solid-state physics is fundamental for this field of thermal physics.