Effective coordination number model for the size dependency of physical properties of nanocrystals

Based on the effective coordination number (ECN) viewpoint a model for the size dependency of cohesive energy of nanocrystals has been developed. In order to calculate ECN both un-relaxed and relaxed surfaces have been considered. It has been shown that bond order-length-strength (BOLS) correlation mechanism can be described successfully by adopting an average ECN approach. Based on ECN and the fundamental effect of cohesive energy on physical quantities, the size dependency of the following parameters has been established: melting temperature, evaporation temperature, Debye temperature, vacancy formation energy of nanocrystals and surface tension of nanodroplets. Predictions for the size dependency of the aforementioned properties are in good agreement with the BOLS model and available results from experimental and simulation studies.