Overview:
A single crystal of a material is one in which the periodic arrangement of atoms in a solid has the same orientation everywhere. In contrast a polycrystal is made up of a large number of single crystals called grains that are separated by grain boundaries. Synthesis of such small particles, single or polycrystalline, of controlled size and shape forms an active area in the field of nanomaterials. Such small nanoparticles have properties different from their bulk (e.g. a chunk of gold that is 1 cm x 1cm x 1 cm) counterparts due to quantum confinement effects and their very large surface to volume ratio. This change is physical properties with a reduction in size to the nanometer regime and the potential application of such differences is what makes nanoparticles scientifically interesting. These Au (111) platelets for example have an inherent tendency to attach to biomolecules such as Cystein, thereby enabling bio-functionalization. This makes them potentially interesting for bio-medical engineering applications.

Studying the structure and properties of particles of such size is not an easy task. It requires the use of advanced characterization techniques such as the Transmission Electron microscope, which has been used to image this particle.