Size Effects on Structure and Morphology of Free or Supported Nanoparticles

Size and Confinement Effects

There are two ways of approaching the properties of nanoscale objects: the bottom-up approach and the top-down approach. In the first, one assembles atoms and molecules into objects whose properties vary discretely with the number of constituent entities, and then increases the size of the object until this discretisation gives way in the limit to continuous variation. The relevant parameter becomes the size rather than the exact number of atoms contained in the object.

    In the second case, one considers the evolution of the properties of a sample as its size is whittled down from macroscopic toward nanometric lengths. It is this approach that we shall examine here, whilst mentioning zones of overlap and exclusion between the two approaches.