Diffusional interpretation of nanoscale solid state wetting in metal systems

Solid state wetting (SSW) seems to be an interesting phenomenon, much less known than the wetting of solid surfaces by liquid droplets. Experimentally the spreading of solid Cu microparticles (0.1-10 μm in size) on Cu surfaces was studied in [1]. In [2] on the basis of molecular dynamics (MD) simulation results we made a conclusion that for metal nanoparticles (1-5 nm in size), including Cu nanoparticles on Cu surfaces, SSW should be even more typical, and this conclusion seems to be quite reasonable. Besides, in [2] we discussed potential application of SSW and some limitations of the usage of nanosized working elements in nanodevices put by SSW. In [2] for MD simulations our computer program was used involving the Verlet velocities algorithm and the tight-binding potential. To increase the reliability of the simulation results, we have also used a well-known and independently developed program LAMMPS which basically proposes the usage of an alternative force field – the embedded atom method. In general the results obtained using LAMMPS agree with the results obtained using our computer program, i.e. both computer programs predict SSW at the nanoscale.

Besides, we have tried to apply a concept of the capillary induced surface diffusion concept (CISDC), combined with some similarity considerations, to predict the characteristic solid state spreading time for metal nanoparticles on the basis of experimental value 3h [1] for Cu microparticles. Some our MD results and results, obtained using CISDC, are presented in Table.

[1] M. Missaen, R. Voytovych, B. Gilles, and N. Eustathopoulos, J. Mater. Sci. 40, 2377–2381 (2005).

[2] V.M. Samsonov, A.G. Bembel, T.E. Samsonov, I.V. Popov, S.A. Vasilyev, Nanotech. in Russia 11, 553–561 (2016).