Features of nanocrystal melting. Issue 1 (11th February 2023) - Zabashta, Yu. F.
Abstract: It is shown that the classical theory of phase transitions is inapplicable for the accurate description of melting processes in nanocrystals. In the paper, the theory of non-classical vacancies is used for this description. In particular, the energy of a nanocrystal containing such defects is evaluated. It is found that the nanocrystal lattice loses its mechanical stability at a certain temperature, T F . This loss of stability is associated with the melting process, and the temperature, T F, is considered as the nanocrystal melting point. At some conditions (for some range of nanocrystal sizes), this temperature may increase with the decrease of the nanocrystal size that agrees with the results of recent experimental studies.