Size dependences of the thermal physical properties of nanoparticles: Entropy and heat of melting

In the thermodynamic theory of phase equilibria in disperse systems, the size dependences of jumps in entropy and the heat of fusion of particles (including those in the nanometer range) are obtained with strict and consistent consideration of surface phenomena in the approach with separating surfaces. The consideration is carried out taking into account the dimensional dependences of the molar volume, melting temperature, and interfacial tension. Using the obtained relations, calculations were performed for spherical sodium and tin nanoparticles. This implies a decrease in the entropy and heat of fusion with decreasing nanoparticle size. The results are in close agreement with the experimental and calculated data available in the literature.