Based on the RP-model of a nanocrystal, an analytical method is developed for calculating the specific surface energy (), isochoric and isobaric derivatives of the function with respect to temperature, and isothermal derivatives of the function with respect to pressure and density. It is shown that the method is applicable for both macro-and nanocrystals with a given number of atoms and a certain surface shape. To implement this method, the parameters of the Mie–Lennard-Jones paired interatomic potential were determined in a self-consistent way based on the thermoelastic properties of the crystal. The method was tested on macrocrystals of 15 single-component substances: for 8-FCC crystals (Cu, Ag, Au, Al, Ni, Rh, Pd, Pt) and for 7-BCC crystals (Fe, V, Nb, Ta, Cr, Mo, W). The calculations were made at different temperatures and showed good agreement with the experimental data. Using the example of FCC-Rh, the change in surface properties with a decrease of the nanocrystal size along the isotherms of 10, 300, 2000 K is studied. It is shown that at high pressures and low temperatures, there is a region where the function increases at an isomorphic-isothermal-isobaric decrease in the nanocrystal size. As the temperature increases, this area disappears.
Зависимость поверхностной энергии от температуры и давления для макро- и нанокристалла
