Nanostructured Materials

The study of nanostructured materials is a very active and exciting area of research and development that has been in progress for the more than a decade. These fine-grained materials often exhibit unique and novel properties that are superior to those of their coarse-grained counterparts. The utilization of advanced techniques of electron microscopy has played and continues to play a pivotal role in the study and development of these materials and the realization of their full potential in many technological applications. This paper first reviews the basic characteristics and properties of nanostructured materials together with some examples of current and future applications. Various synthesis and processing methods are briefly described, pointing out the very important role that synthesis and processing have on the ensuing properties. The critical function of advanced electron optical techniques have in the progress of these materials is illustrated by three original examples. These examples refer to the use of detailed microstructural analysis to get a better understanding on the nature of grain boundaries and its effects on properties; the use of microstructural analysis to study and to understand the effects of grain size, chemical composition and microstructural constraints on the thermal stability and the mechanical behavior of nanocomposites for high temperature use; and, the properties of fullerene-reinforced nanocomposites are briefly reviewed. The paper concludes with a retrospective view on the importance: in clearly differentiating between intrinsic and extrinsic grain boundary facets and in accounting fully for the contamination products that may present, all of which profoundly affect the resulting properties.