In situ determination of the shape of supported silver clusters during growth

摘要: Abstract The dependence of the shape metal nanoparticles generated on surface wide bandgap materials has been investigated in situ during growth. For this purpose, silver clusters with diameters ranging from 0.8 to 10 nm were fabricated ultrahigh vacuum quartz surfaces by deposition atoms and subsequent Volmer–Weber During sample preparation substrate temperature was chosen be either T=300 or 700 K. size particles determined an approach combining non-contact scanning force microscopy (SFM) optical spectroscopy. Made at room temperature, mean below 1 nm are found almost spherical whereas larger become more oblate growth, axial ratio decreasing unity 0.4. In contrast, if is held 700 K cluster turn out irrespective their size. results explained size- temperature-dependent relaxation times need reach equilibrium shape.