Study of size effect on thermophysical properties of metallic nanosolids

In the present study, a phenomenological model based on thermodynamic variables is developed to study the thermophysical properties of nanomaterials with respect to size in nanoscale. The model input parameters are lattice packing fraction depending on crystal structure and atomic diameter of nanosolid. The shape parameter is incorporated in the model to study the variation in physical properties of metallic nanosolids with shape. The size and shape effect on melting temperature 𝑇𝑀𝑁, Debye temperature θ𝐷𝑁, Specific heat capacity 𝐶𝑁, thermal conductivity 𝐾𝑁 and electrical conductivity σ𝑁 is studied in metallic nanosolids. It is observed from the results obtained that both melting temperature and Debye temperature get reduced with reduction in size of nanosolid. Also Thermal conductivity and electrical conductivity in nanosolids decrease as size reduces. This is due to the increase in the number of surface atoms with size reduction and pronounced quantum confinement in nanomaterials. Also, the drastic change in number of surface atoms with the change in shape of the nanomaterial of same size brings about change in its thermophysical properties. The present model results are found consistent with the available experimental and simulated results of previous workers and may be useful for experimental researchers exploring the physical properties of nanomaterials.