The formation of penta-twinned gold particles

The formation of gold particles containing five radially arranged twin boundaries (called penta-twinned particles) has been investigated by means of high-resolution transmission electron microscopy. The particles were produced by evaporation of gold in helium at low pressure (0.5 kPa). The processes involved in the formation of the particles are deduced from the experimentally observed size distribution, the characteristic particle morphologies and the frequency of different particle structures. The penta-twinned particles are suggested to be formed by the collision and rearrangement of small single crystals in the helium atmosphere. (orig.)