Effect of size and shape on melting and superheating of free standing and embedded nanoparticles

A simple model is proposed to study the size and shape dependence of melting and superheating of nanomaterials. The size dependence of melting temperature of free standing spherical nanosolids viz. Ag, Au, Al and Zn nanowire as well as embedded nanoparticles Pb and Ag is reported. The formulation is used to study the effect of shape on melting temperature during reduction of size. The different shapes of nanomaterials viz. film, icosahedral, wire, spherical, hexahedral, octahedral and tetrahedral are considered. The size and shape dependence of surface atoms, total number of atoms and their ratio is computed. The results obtained are compared with the available experimental data and discussed in the light of recent investigations. A good agreement between model predictions and experimental data supports the validity of the formulation developed. It is concluded that in addition to the size, the shape of nanomaterials also plays an important role during the behaviour of nanomaterials.