Effect of substrates on the melting temperature of gold nanoparticles

The size-dependent melting temperature of metallic nanoparticles (NPs) is generally examined on a solid substrate. However, most experimental works performed on a solid substrate were explained by a homogeneous particle model without considering the effect of the substrate. For example, in the previous studies, the melting temperatures of gold NPs were examined on carbon or tungsten substrates. However, the experimental results were described only by the surface tension of gold, without interfacial tension between gold and substrate. In the present work, the effect of the sorts of substrate on the melting temperatures of gold NPs was examined by using a thermodynamic model equilibrating the chemical potentials of liquid and solid particles. For this study, graphite, alumina and tungsten substrates were selected as typical ceramic and metallic substrates.