Field assisted sintering of nickel nanoparticles during in situ transmission electron microscopy

摘要

This study reports the in situ transmission electron microscopy (TEM) observation of pressure-less field-assisted sintering of agglomerated nanometric nickel particles. Scanning tunneling microscopy inside the TEM was used to apply an electrical current directly to the powder particles. Electrical testing during the experiment reveals that consolidation occurs in the absence of an external heat source. Neck formation between adjacent particles and attendant increase in local Joule heating causes rapid densification. The results represent a first stepping stone towards achieving a fundamental mechanistic understanding of the atomic-scale processes that enable field-enhanced sintering of conductive nanogranular materials.