Thermal Properties -- Melting Point

The melting point of a nanomaterial changes drastically compared with the bulk material's melting point, and this change itself depends on exactly how small the particles are -- melting point is not a fixed property once a material is reduced to the nanoscale, but instead varies continuously with particle size. The chapter's illustrating data comes from sodium clusters: a cluster of 1,000 sodium atoms (Na1000) was found to melt at 288 K, while a larger cluster of 10,000 sodium atoms (Na10000) melted at a higher temperature, 303 K -- and bulk sodium metal, for comparison, melts at a still-higher 371 K. The pattern across these three data points is clear and consistent: as the cluster size increases from 1,000 atoms toward the fully bulk material, the melting point rises steadily toward the bulk value, showing that melting point at the nanoscale is a genui …