The formation and dissociation energy of vacancies in cementite: A first-principles study

Because of the possibility of various types of vacancies in cementite due to its crystalline structure, the focus of this paper was only on vacancies. In this regard, the formation energies of single, two, three and four vacancies of over than 120 different cases were calculated using first-principles method. For the case of single vacancy, the results were in three values of similar to 1.63, 1.39 and 0.78 eV according to iron vacancies at general positions, iron vacancies located on mirror planes and carbon vacancies in the interstitial positions, respectively. The results for the case of two, three and four vacancies were between from 2.10 to 3.34 eV, from 3.92 to 5.10 eV and from 4.77 to 6.33 eV, respectively. The dissociation energies of clusters with 2, 3 and 4 vacancies were also calculated to be 0.917, 0.988 and 1.166, respectively.

Automated summary

This paper focused on vacancies in cementite due to its crystalline structure, and calculated the formation energies of single, two, three and four vacancies in over 120 different cases using first-principles method. The results showed different values for single vacancies at different positions, while the formation energies for two, three and four vacancies fell within specific ranges. Additionally, the dissociation energies of clusters with 2, 3 and 4 vacancies were also calculated.