Room Temperature Nanojoining of Triangular and Hexagonal Silver Nanodisks

Room temperature nanojoining is an important phenomenon that has to be understood well for use in different applications, for example, for assembly of nanoscale building blocks into nanoscale and microscale structures and devices. However, the mechanism for nanoparticle joining at room temperature is not well established. In this research, we employed molecular dynamics simulation to explain how and why silver nanodisks are joined/assembled but with their original shape unchanged. To support our theoretical observations, we compared our simulation results to SEM and HRTEM observations of joined silver nanodisks. It was found that joining at a wide temperature range (1-500 K) can be done through short movement and rearrangement of surface atoms and subsequent elastic or plastic deformation of the particles, resulting in perfect crystal alignment at the joint interface. Our simulation shows the crystal defects such as dislocations due to initial lattice mismatch of the crystals can be sintered out to yield a perfect crystalline structure at the interface between joined particles, which is supported by the experimental observations.