Calculations on Formation and Binding Energies with Bulk Vacancies and (001) Surface of α-Fe

Both formation and binding energies,of mono-vacancy and di-vacancy of the bulk and first five layers on(001) surface in BCC metal αFe,are calculated by using the modified analytical embedded-atom method in order to understand the effect of the vacancies to the physical,chemical and mechanical properties.Mono-and di-vacancy can form easily,based on calculation,in the first layer of surface atom associated with minimum formation energy.a di-vacancy in the first layer is the most stable,corresponds to maximum binding energy,nearest-neighbor d between first and second layer is next.As that the migration and collection of vacancies in surface layer of α-Fe is clear.