Burrowing of nanoparticles on clean metal substrates: Surface smoothing ona nanoscale - art. no. 085419

We have investigated soft landings of Co nanoparticles on clean Cu(001) sur faces. The nanoparticles, approximate to 10 nm in size, were generated by d e magnetron sputtering in argon and transferred in the gas stream to an ult rahigh vacuum transmission electron microscope (TEM), where they were depos ited on the thin-film substrate. The surface morphology created in this fas hion exhibits a unique smoothing mechanism. The nanoparticles do not remain on the surface at temperatures as low as 600 K, but rather reorient and bu rrow into the substrate. By analyzing the TEM data in combination with mole cular dynamics simulations, we were able to study this process in detail an d to develop a model to quantify the temperature and cluster size dependenc e of burrowing.