Nanoscale materials, recent applications development

In recent years much effort has been spent on the development of experimental techniques to grow well defined nanoscale materials, due to their possible applications in nanometric electronic devices. Indeed the creation of nanowire field effect transistors [128-132], nano-sensors [133,134], atomic scale light emitting diodes and lasers [135,136], has been made possible by the development of new techniques, which allow one to control the growth processes of nanotubes, nanowires and quantum dots. Of particular importance, among the different atomic scale systems experimentally studied, are... 

Nanoscale materials are those with dimensions less than 100 nm. Most of the nanomaterials used, such as oxides, sulfides, nitrides, and others are well known, in many cases since the beginning of civilization. In recent decades, it has been observed that specific properties of these materials, useful in biomedical, electromagnetic, mechanical, and catalytic areas," can be enhanced by reducing particle size to nanoscale dimensions. Many synthetic strategies have been developed in order to obtain nanometric materials with specific properties. Thin films of powders, in particular, have been the subject of current investigations. Studies of new synthetic approaches for nanometric films are intimately connected with the development of the chemical vapor deposition technique, which has widespread acceptance and is used for the production of important supplies for semiconductor electronic applications. ... 

The LBL method can also be used for the assembly of nanoparticles on suitable colloid templates. This procedure was recently developed by Caruso et al. ° and has found application in a great variety of materials. In this system, the optical effects observed for the macroscopic thin films are obtained for colloidal particles, which possess themselves a core-shell geometry and can be used in turn for the construction of more complex, nanoscale materials. The resulting spheres are essentially different to continuous metal shells grown on colloid templates, which have been recently reported. " Such continuous shells display optical properties associated to resonances along the whole shell, and are therefore extremely sensitive to both core size and shell thickness, while in the system presented here the optical properties only depend on the nature and dimensions of the constituting units and the number of deposited monolayers. 

Recent progress in electron diffraction has significantly broadened its applications from a primary a microstructure characterization tool to an accurate structure analysis technique that traditionally belongs almost exclusively to the domain of X-ray and neutron diffraction. This development is timely since the focus of modem materials feature size is increasingly on nanoscale stmctures, where the electron high spatial... 

Nanotechnology and surface science In recent decades, for example, the application of nanoscience and nanotechnology has developed since the molecular studies of surfaces at nanoscale have reached a much higher level. Nanotechnology is now a popular topic in materials science, and other areas are also emerging. It has deserved this popularity because of its interdisciplinary character, calling for expertise in physics, chemistry, biology, and medicine. Many materials properties are studied in detail. 

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