Mechanism of Heat-Induced Fusion of Silver Nanowires

Physical changes in arranged silver nanowires were monitored during progressive heating inside a transmission electron microscope. Using the in-situ experimental method, overall variation of silver nanowires and movement of the silver atoms could be assessed. The physical morphology of silver nanowires was rapidly transformed above 350 degrees C as they fused with each other, which led to extrusion of the silver atoms. Around 550 degrees C, silver nanowires were almost fused into one, filling a relatively large void between silver nanowires. However, above 575 degrees C, the united silver nanowire was completely cut off, starting from the region that was suspected to have defects. For the first time, the fusion of arranged silver nanowires and the configurational changes of silver atoms during heating were visualized, and the migration between silver atoms and the damage mechanism of silver nanowires were assessed. Moreover, the relationship of physical morphology and electrical property of silver nanowires according to the temperature were investigated using the ex-situ experimental method. As silver nanowires started to split at 300 degrees C, the electrical conductivity deteriorated greatly. Beyond 350 degrees C, the electrical conductivity was completely lost while silver nanowires disintegrated rapidly, and silver nanowires completely disappeared at 450 degrees C.