In their work (Nanotechnology 23 135707 and Nanotechnology 22 445703), researchers from the Institute of NanoSciences, France, have used UV-visible differential reflectivity spectroscopy to monitor silver vapour deposition on alumina crystals in UHV conditions as a function of temperature and flux. Spectra were analysed via dielectric modelling of particles represented by truncated spheres and by including size- and temperature-dependent corrections.

Nucleation on defects, growth at constant particle density and dynamic coalescence involving cluster diffusion were clearly highlighted. These growth steps were associated with the power law evolution with time of particle size and density. The size-dependent aspect ratio of the silver nanoclusters was assigned to a combination of epitaxial and surface stresses.

Monitoring the plasmonic response of the sample revealed itself to be a unique in situ technique for pinpointing such rarely observed effects on particles supported on a bulk insulating substrate. Beyond the case of growth on a surface, this work opens up perspectives in morphology characterization during the course of heterogeneous catalytic reactions, gas sensing or catalyzed growth of carbon nanotubes.

Additional information can be found in the journal Nanotechnology.