Bonding of Cr and V in FeAl B2 phase

Abstract

Ab initio calculations of the properties of the FeAl B2 phase alloyed by Cr or V are performed on the basis of the full potential augmented plane-wave (APW) ϩ local orbitals (lo) method. The site preference occupation for Cr and V atoms in this compound is investigated. We studied the changes in the site preference for Cr and V substituting for Fe or Al when the vacancy on the Fe site is formed. Existence of the vacancy significantly changes the site occupation preference for Cr that transits from the Al site to the Fe site. The site occupation preference for these alloying elements in the compound is explained in terms of the electronegativity of surrounding atoms and the effective charges of transition metals.

The influence of doping by transition metal elements on the vacancy formation energy in Fe-Al B2 phase

“…This analysis was based on a comparison of the mixing energies following the scheme presented in previous work. [20] It was also reported that Cr and V occupy the Al site in the ideal Fe-Al B2 phase. In the case of a vacancy on the Fe site in Fe-Al, V occupies the Al site and Cr occupies the Fe site nearest to the vacancy.…”

“…The vacancies in the Fe-Al B2 phase are formed mainly on the Fe sublattice [20] ; therefore, it is of interest to check the influence of the alloying transition metal (TM) on the preference site for the vacancy formation. The calculated results are summarized in Table 2.…”

“…[18] Alloying elements affect the energy of the vacancy formation, and therefore they influence the diffusion mechanics. [20] In the present article, we report the results of our study of the influence of Ni, Cr, and V on the energy of vacancy formation on both Fe and Al sites in Fe-Al.…”

Structural Channels as Natural Tracks in Crystal

“…The Density Functional Theory (DFT) has been applied [29][30][31][32][33][34][35], and the mixing energy for the Ni 12 P 5 + Li system has been calculated as well as the spatial distribution of differential electron density (DED) and the Density of States (DOS) for the system. The software package WIEN2k-09.2 [36] was used for the electronic structure calculations.…”

Influence of alloying on the thermodynamic stability of FeAl B2 phase

“…Presence of these defects in FeAl has significant influence on the material properties stimulating the research aimed to use peculiar defect behaviour for improving material performance [3e6]. We found, in our previous works, that the vacancies exist mainly on the Fe sublattice [7] and the anti-sites are more feasible energetically on the Al sublattice [8] in FeAl B2 phase. These results are in agreement with experimental and theoretical studies [9e11].…”