Room temperature molecular dynamics simulations on the sintering of cu-Ag core-shell structures: Nanoparticles and nanowires

Atomistic understanding of sintering mechanism is conducive to improve industrial applications such as printable nanoinks, electrodes, and catalysts. Nanojoining by sintering of nanoparticles and nanowires with different geometries are examined at room temperature (300K) with molecular dynamics simulations. The evolution of potential energy and local crystalline structure during sintering process are analyzed to identify sintering mechanisms. Depending on geometry, different sintering mechanisms including crystallization-Amorphization, rotation, Shockley partial dislocation are detected. In all simulation cases, Cu core does not participate in sintering process, while it plays the role of enhancing the mobility of Ag shell atoms. In nanowire sintering, a three-stage scenario is also observed, similar to that of core-shell NP sintering. The Young's modulus and yield strength of sintered nanowire obtained from tensile test are different from the reported values since they depend on many other parameters, such as NW size, strain rate, and temperature.