Phonon Engineering Theory Of Crystalline Layered Nanostructures

Application of nano-structures requires knowledge of their fundamental physical (mechanical, electro-magnetic, optical, etc.) characteristics. Thermodynamic properties associated with phonon displacements through the nano-samples are particularly interesting. Independent of the type of lattices, the thermodynamics of their subsystems (electrons, excitons, spin waves, etc.) is determined when the subsystem is in thermodynamic equilibrium with phonons. Besides, the acoustical characteristics as well as conductive and superconductive properties etc. could not be realistically explained without phonons. The fact which must be especially pointed out is that the role of phonons in nanostructures is much more impressive than in bulk structures. The main fact concerning phonon properties in nanostructures is the absence of the so-called acoustic phonons: for the exciting of phonons in nanostructures activation energy different from zero is necessary. These unexpected characteristics require revision of all conclusions obtained by bulk theories of phonons. Therefore, the contribution of phonon subsystems to thermodynamic is the first step in a research of nanostructure properties.

With the development of the scanning tunneling microscope, nanoscience became an important discipline. Single atoms could be manipulated in a controlled manner, and it became possible to change matter at its 'ultimate' level; it is the level on which the properties of matter emerge. This possibility enables to construct and to produce devices, materials, etc. with very small sizes and completely new properties. That opens up new perspectives for technology and is in particular relevant in connection with nano-engineering.Nanosystems are unimaginably small and very fast. No doubt, this is an important characteristic. But there is another feature, possibly more relevant, in connection with nanoscience and nanotechnology. The essential point here is that we work at the 'ultimate level'. This is the smallest level at which the properties of our world emerge, at which functional matter can exist. In particular, at this level biological individuality comes into existence. This situation can be expressed in absolute terms: This is not only the strongest material ever made, this is the strongest material it will ever be possible to make (D Ratner and M Ratner, Nanotechnology and Homeland Security). This is a very general statement. All aspects of matter are concerned here. Through the variation of the composition various forms of matter emerge with different items.Nanosystems are usually small, but they offer nevertheless the possibility to vary the structure of atomic (molecular) ensembles, creating a diversity of new material-specific properties. A large variety of experimental possibilities come into play and flexible theoretical tools are needed at the basic level. This is reflected in the different disciplines: In nanoscience and nanotechnology we have various directions: Materials science, functional nanomaterials, nanoparticles, food chemistry, medicine with brain research, quantum and molecular computing, bioinformatics, magnetic nanostructures, nano-optics, nano-electronics, etc.The properties of matter, which are involved within these nanodisciplines, are ultimate in character, i.e., their characteristic properties come into existence at this level. The book is organized in this respect.

With the development of the scanning tunneling microscope, nanoscience became an important discipline. Single atoms could be manipulated in a controlled manner, and it became possible to change matter at its 'ultimate' level; it is the level on which the properties of matter emerge. This possibility enables to construct and to produce devices, materials, etc. with very small sizes and completely new properties. That opens up new perspectives for technology and is in particular relevant in connection with nano-engineering.Nanosystems are unimaginably small and very fast. No doubt, this is an important characteristic. But there is another feature, possibly more relevant, in connection with nanoscience and nanotechnology. The essential point here is that we work at the 'ultimate level'. This is the smallest level at which the properties of our world emerge, at which functional matter can exist. In particular, at this level biological individuality comes into existence. This situation can be expressed in absolute terms: This is not only the strongest material ever made, this is the strongest material it will ever be possible to make (D Ratner and M Ratner, Nanotechnology and Homeland Security). This is a very general statement. All aspects of matter are concerned here. Through the variation of the composition various forms of matter emerge with different items.Nanosystems are usually small, but they offer nevertheless the possibility to vary the structure of atomic (molecular) ensembles, creating a diversity of new material-specific properties. A large variety of experimental possibilities come into play and flexible theoretical tools are needed at the basic level. This is reflected in the different disciplines: In nanoscience and nanotechnology we have various directions: Materials science, functional nanomaterials, nanoparticles, food chemistry, medicine with brain research, quantum and molecular computing, bioinformatics, magnetic nanostructures, nano-optics, nano-electronics, etc.The properties of matter, which are involved within these nanodisciplines, are ultimate in character, i.e., their characteristic properties come into existence at this level. The book is organized in this respect.

The monograph is devoted to the investigation of physical processes that govern the phonon transport in bulk and nanoscale single-crystal samples of cubic symmetry. Special emphasis is given to the study of phonon focusing in cubic crystals and its influence on the boundary scattering and lattice thermal conductivity of bulk materials and nanostructures.

This book focuses on the theory of phonon interactions in nanoscale structures with particular emphasis on modern electronic and optoelectronic devices. The continuing progress in the fabrication of semiconductor nanostructures with lower dimensional features has led to devices with enhanced functionality and even novel devices with new operating principles. The critical role of phonon effects in such semiconductor devices is well known. There is therefore a great need for a greater awareness and understanding of confined phonon effects. A key goal of this book is to describe tractable models of confined phonons and how these are applied to calculations of basic properties and phenomena of semiconductor heterostructures. The level of presentation is appropriate for undergraduate and graduate students in physics and engineering with some background in quantum mechanics and solid state physics or devices. A basic understanding of electromagnetism and classical acoustics is assumed.

The book is devoted to nanostructures and nanostructured materials containing both amorphous and crystalline phases with a particular focus on their thermal properties. It is the first time that theoreticians and experimentalists from different domains gathered to treat this subject. It contains two distinct parts; the first combines theory and simulations methods with specific examples, while the second part discusses methods to fabricate nanomaterials with crystalline and amorphous phases and experimental techniques to measure the thermal conductivity of such materials. Physical insights are given in the first part of the book, related with the existing theoretical models and the state of art simulations methods (molecular dynamics, ab-initio simulations, kinetic theory of gases). In the second part, engineering advances in the nanofabrication of crystalline/amorphous heterostructures (heavy ion irradiation, electrochemical etching, aging/recrystallization, ball milling, PVD, laser crystallization and magnetron sputtering) and adequate experimental measurement methods are analyzed (Scanning Thermal Microscopy, Raman, thermal wave methods and x-rays neutrons spectroscopy).