Are There Ways to Synthesize Materials Beyond the Limits of Today?

摘要

A growing number of studies in recent years indicate that the preparation methods or the diagnostic tools developed in nanoscience and nanotechnology (NS/NT) may be used to synthesize materials beyond the limits of today. In this article, the following three kinds of materials synthesized by means of this approach are discussed. (1) Materials with tuneable atomic structures and densities. They are synthesized by introducing a high density of interfaces (i.e., interfaces spaced a few nanometers) into glasses and by subsequently delocalizing the enhanced free volume associated with these interfaces. (2) The alloying of conventionally immiscible components in the form of solid solutions. The alloying process is achieved by generating nanocomposits of these immiscible components. Due to the electronic space charge associated with the resulting interphase boundaries, the electronic structure of the nanocomposits is modified in the vicinity of the interphase boundaries. This modification changes the mutual solubility of the components so that even components that are completely immiscible in the electrically neutral state (such as Ag and Fe) form solid solutions in the space charge regions. (3) Self-assembled materials the atomic structure of which may be modified so that switches of atomic size are formed. The conductance of these switches is entirely controlled by an externally applied voltage without any mechanical movement of electrodes, etc. Reproducible switching was performed between an electrically insulating (“off”) state and many “on” states each of which is characterized by a preselectable conductance. Materials of this kind may open new perspectives for quantum electronics and the development of logics on an atomic scale. The three examples discussed in this article represent just three out of many other facets of a newly developing branch of nanoscience. This branch is characterized by the application of preparation methods or diagnostic tools—pioneered in nanoscienceanotechnology—to perform new studies in a variety of other areas of science such as molecular biology, medicine, quantum physics, and astronomy.