ABSTRACT

If an inorganic cluster exceeds a certain size, generally in the tens of unit cells, then it will likely possess a bonding geometry characteristic of a bulk phase3,4. Above this critical size, the nature of the chemical bonds in the cluster remains fixed as a function of the size, but the total number of atoms, or the surface to volume ratio, change smoothly. This leads to a slow extrapolation of the properties of ideal nanocrystals towards bulk values with increasing size, according to the scaling laws. The ability to systematically control the properties of inorganic materials by variation of size and shape is an important development, with many implications for how materials should be processed and assembled5.