Ab-initio calculations of the formation energies of BCC-based superlattices in the FeAl system

Ab Initio calculations of phase stabilities in the Fe−Al−C system and CALPHAD-Type assessment of the iron-rich corner

“…Calculations have been performed on the stoichiometric compound. Our result of À32.2 kJ/ mol for the formation enthalpy agrees within 615 pct, with the values obtained by Lechermann [25,26] and Gonzales [27] with other DFT techniques ( Figure 2). It is in the range of the calorimetric results that span from À24 to À40.5 kJ/mol (Reference 28).…”

“…Thermo-Calc calculations allow for the determination of ternary isotherms. Our calculations agree within 64 kJ/mol with the DFT calculations of Gonzales [27] and Lechermann. [29] Fig.…”

“…Such a high discrepancy is rather unexpected. In fact, our calculations on the binary compounds show an uncertainty of less than 62 kJ/mol, or equivalently 610 pct, between our VASP calculations and the calculations of Lechermann [29] and of Gonzales [27] with, respectively, the WIEN2k and WIEN97 software.…”

“…For comparison, Lechermann with FLAPW finds À18.9 kJ/mol in LSDA and À21.2 kJ/mol in GGA. Gonzales [27] with FLAPW finds À21.5 kJ/mol in the GGA approximation. Our result is in the range of the preceding literature results.…”

Embedded atom method study of the interactions between point defects in iron aluminides: Double defects

“…the potentials are fitted using experimental data, among them the experimental formation enthalpies of the D0 3 and B2 superlattices in the system, in other words the B2 phase has to be more stable than B32; and 2. one important degree of freedom is not considered in the calculation: the spin orientation of the iron atoms, which is expected to play an important role at low temperatures [32][33][34]. Fig.…”