ABSTRACT
Interest in the evolution of physical properties from atoms to bulk materials is a growing area of materials science. Because clusters of various sizes could represent transitional states from atoms or molecules to solids, they became powerful investigative tools. Experimental techniques for production of clusters comprising metallic, semiconducting, and insulating atoms in various numbers have progressed in recent decades, bringing deep understanding of the differences and similarities of materials’ evolution [1], such as when does a metal become a metal, and when does a cluster mimic the structure of a bulk solid? Answers to such questions have interested even those who are not scientists. For these questions, however, there was not a single answer, because various materials exhibit different evolutions of their properties with size [2]. Advances in these areas of research contribute not only to fundamental understanding, but also to many areas of technical applications, such as in chemical engineering, optical, magnetic, and electrical device fabrications. Many technical review papers and books have been published on this subject [3-6].
