This work compares the morphology of gold nanoparticles (NPs) produced at room temperature on single-crystalline (MgO nanocubes and plates) and amorphous (carbon/glass plates) substrates by pulsed laser deposition (PLD). The results show that similar deposition and nucleation rates $\left(>5\times {10}^{13}{\text{cm}}^{-2}{\text{s}}^{-1}\right)$ are achieved irrespective of the nature of the substrate. Instead, the shape of NPs is substrate dependent, i.e., quasispheres and faceted NPs in amorphous and single-crystalline substrates, respectively. The shape of the latter is octahedral for small NPs and truncated octahedral for large ones, with the degree of truncation being well explained using the Wulff-Kaichew theorem. Furthermore, epitaxial growth at room temperature is demonstrated for single-crystalline substrate. The large fraction of ions having energies higher than 200 eV and the large flux of species arriving to the substrate $\left({10}^{16}\text{at}\text{.}{\text{cm}}^{-2}{\text{s}}^{-1}\right)$ involved in the PLD process are, respectively, found to be responsible for the high nucleation rates and epitaxial growth at room temperature.

• Received 1 December 2008
• Corrected 11 June 2009

DOI:https://doi.org/10.1103/PhysRevB.79.235409