Liquid-to-crystal nucleation has been studied extensively through droplet experiments to locate examples of homogeneous nucleation. However, prior to this work very few examples have been found, which implies that the experiments have not been able to isolate heterogeneous nucleants in a small percentage of the droplets as is required. In this research, electrohydrodynamic atomization (EHD) is used to produce sub-Micron droplets of pure elements that are largely free of heterogeneous nucleants.
Diffraction patterns of individual EHD-produced droplets are viewed to determine the fraction of crystalline droplets produced as a function of droplet radius. These results are compared to theories for surface and volume heterogeneous nucleation and for homophase nucleation. It is found that Si and Ge nucleate through either homogeneous nucleation or nucleation by homophase impurities. Nucleation results for vanadium and iron were not conclusive.