In this Brief, authors introduce the advance in theoretical and experimental techniques for determining the thermal conductivity in nanomaterials, and focus on review of their recent theoretical studies on the thermal properties of silicon–based nanomaterials, such as zero–dimensional silicon nanoclusters, one–dimensional silicon nanowires, and graphenelike two–dimensional silicene. The specific subject matters covered include: size effect of thermal stability and phonon thermal transport in spherical silicon nanoclusters, surface effects of phonon thermal transport in silicon nanowires, and defects effects of phonon thermal transport in silicene. The results obtained are supplemented by numerical calculations, presented as tables and figures. The potential applications of these findings in nanoelectrics and thermoelectric energy conversion are also discussed. In this regard, this Brief represents an authoritative, systematic, and detailed description of the current status of phonon thermal transport in silicon–based nanomaterials. This Brief should be a highly valuable reference for young scientists and postgraduate students active in the fields of nanoscale thermal transport and silicon-based nanomaterials.

Due to the technological significance of silicon, its heat conduction mechanisms have been studied extensively. However, there have been some lingering questions surrounding the phonon mean free path and importance of different polarizations. This research investigates phonon transport in bulk crystalline silicon using molecular dynamics and lattice dynamics. The interactions are modeled with the environment dependent interatomic potential (EDIP), which was designed to represent the bulk phases of silicon. Temperature and phonon frequency dependent relaxation times are extracted from the MD simulations and used to generate a detailed picture of phonon transport. It is found that longitudinal acoustic phonons have the highest contribution to thermal conductivity and that the phonon mean free path varies by orders of magnitude with respect to the phonon spectra. For relaxation times, we observe moderate anisotropy and good agreement with the frequency dependence predicted by scattering theories. We also find that phonons with mean free paths between .1 and 10 micron are responsible for 50% of the thermal conduction, while phonons with wavelengths less than 10 nanometers make up 80%.

The vibrations of atoms inside crystals - lattice dynamics - is basic to many fields of study in the solid-state and mineral sciences. This book provides a self-contained text that introduces the subject from a basic level and then takes the reader through applications of the theory.

The Boltzmann transport equation derived in the Self-Adjoint Angular Flux (SAAF) formulation is applied to simulate phonon transport. The neutron transport code Rattlesnake is leveraged in this fashion, slightly modi ed to accept input from variables consistent with phonon transport simulations. Several benchmark problems are modeled to assess the potential of this application to predict thermal conductivity in materials with heterogeneity and isotopic fission products affecting thermal transport. The 1-D, SAAF formulation of the Boltzmann transport equation for phonons is derived along with associated boundary conditions. Comparisons to phonon transport problems solved via deterministic, Monte Carlo (MC) and molecular dynamics (MD) methods are shown. Phonon intensity and heat flux are used to compute thermal conductivity in materials. Phonon transport with Rattlesnake using similar input conditions compares well to test problems in open literature. Transport is simulated in one and two element systems, with special emphasis on uranium dioxide (UO2) with xenon cluster defects. Rattlesnake solutions show thermal conductivity in UO2 decreasing by up to a factor of 4 at elevated temperatures. Transport behavior for these problems appears qualitatively correct, though lack of data for xenon properties yields results which deviate from MD simulations. Results are generally favorable, though the current deterministic phonon transport implementation does not include certain phonon scattering physics. Further development of Rattlesnake is discussed, with an emphasis on coupling with phase fields for better characterization of microstructure in nuclear fuel.

Beginning with an overview of nanomachining, this monograph introduces the relevant concepts from solid-state physics, thermodynamics, and lattice structures. It then covers modeling of thermal transport at the nanoscale and details simulations of different processes relevant to nanomachining. The final chapter summarizes the important points and discusses directions for future work to improve the modeling of nanomachining.

This is a graduate level textbook in nanoscale heat transfer and energy conversion that can also be used as a reference for researchers in the developing field of nanoengineering. It provides a comprehensive overview of microscale heat transfer, focusing on thermal energy storage and transport. Chen broadens the readership by incorporating results from related disciplines, from the point of view of thermal energy storage and transport, and presents related topics on the transport of electrons, phonons, photons, and molecules. This book is part of the MIT-Pappalardo Series in Mechanical Engineering.

Transport Phenomena in Micro- and Nanoscale Functional Materials and Devices offers a pragmatic view on transport phenomena for micro- and nanoscale materials and devices, both as a research tool and as a means to implant new functions in materials. Chapters emphasize transport properties (TP) as a research tool at the micro/nano level and give an experimental view on underlying techniques. The relevance of TP is highlighted through the interplay between a micro/nanocarrier's characteristics and media characteristics: long/short-range order and disorder excitations, couplings, and in energy conversions. Later sections contain case studies on the role of transport properties in functional nanomaterials. This includes transport in thin films and nanostructures, from nanogranular films, to graphene and 2D semiconductors and spintronics, and from read heads, MRAMs and sensors, to nano-oscillators and energy conversion, from figures of merit, micro-coolers and micro-heaters, to spincaloritronics. - Presents a pragmatic description of electrical transport phenomena in micro- and nanoscale materials and devices from an experimental viewpoint - Provides an in-depth overview of the experimental techniques available to measure transport phenomena in micro- and nanoscale materials - Features case studies to illustrate how each technique works - Highlights emerging areas of interest in micro- and nanomaterial transport phenomena, including spintronics