Formation of Metallic Nanowires by Laser Ablation in Liquid Helium

Laser ablation of metals in liquid helium results in the formation of metal filaments with diameters on the order of 2-10 nanometres and of spherical nanoparticles. In superfluid helium these nanowires aggregate into centimeter-sized networks. We study the morphology and the electric conductivity of these large aggregates, as well as extinction spectra and the crystalline structure of the individual nanofragments. We discuss the effect of superfluidity on the mechanisms of coalescence processes at the nanometer and centimeter scales.