The Formation and Dynamic Evolution of Antiphase Domain Boundary in FeAl Alloy: Computational Simulation in Atomic Scale

Wang, Kun; Wang, Yongxin; Cheng, Yanfeng

doi:10.1590/1980-5373-mr-2017-1048

Cited by 11 publications

(5 citation statements)

References 50 publications

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“…It disturbs the chemical order of the next nearest neighbors (APB-NNN type, also called the APB-D03 type). Other studies followed more recently [45,46,47,48,49]. As some parts of Fe3Al samples after cooling can exist in the higher temperature B2 lattice (and not the low temperature D03 superlattice; see, e.g., [49]) and the APBs with 1/4〈111〉 a can exist in both types of lattices, we focus our study on the D03 type (APB-NNN) of APBs with the 1/2〈100〉 a shift, which are specific to the D03 lattice of Fe3Al.…”

Section: Introductionmentioning

confidence: 99%

A Quantum–Mechanical Study of Clean and Cr–Segregated Antiphase Boundaries in Fe3Al

2019

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We present a quantum-mechanical study of thermodynamic, structural, elastic, and magnetic properties of selected antiphase boundaries (APBs) in Fe3Al with the D03 crystal structure with and without Cr atoms. The computed APBs are sharp (not thermal), and they have {001} crystallographic orientation. They are characterized by a mutual shift of grains by 1/2〈100〉a where a is the lattice parameter of a cube-shaped 16-atom elementary cell of Fe3Al, i.e., they affect the next nearest neighbors (APB-NNN type, also called APB-D03). Regarding clean APBs in Fe3Al, the studied ones have only a very minor impact on the structural and magnetic properties, including local magnetic moments, and the APB energy is rather low, about 80 ± 25 mJ/m2. Interestingly, they have a rather strong impact on the anisotropic (tensorial) elastic properties with the APB-induced change from a cubic symmetry to a tetragonal one, which is sensitively reflected by the directional dependence of linear compressibility. The Cr atoms have a strong impact on magnetic properties and a complex influence on the energetics of APBs. In particular, the Cr atoms in Fe3Al exhibit clustering tendencies even in the presence of APBs and cause a transition from a ferromagnetic (Cr-free Fe3Al) into a ferrimagnetic state. The Fe atoms with Cr atoms in their first coordination shell have their local atomic magnetic moments reduced. This reduction is synergically enhanced (to the point when Fe atoms are turned non-magnetic) when the influence of clustering of Cr atoms is combined with APBs, which offer specific atomic environments not existing in the APB-free bulk Fe3Al. The impact of Cr atoms on APB energies in Fe3Al is found to be ambiguous, including reduction, having a negligible influence or increasing APB energies depending on the local atomic configuration of Cr atoms, as well as their concentration.

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Section: Introductionmentioning

confidence: 99%

A Quantum–Mechanical Study of Clean and Cr–Segregated Antiphase Boundaries in Fe3Al

2019

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“…An experimental evidence of the co-existence of Fe3Al and a disordered Fe-Al phase has been provided, for example, by transmission electron microscopy (TEM) technique which is sensitive to anti-phase boundaries (APBs). The APBs have a different character in Fe3Al intermetalics and in the Fe-Al phase [14,15,16,17]. Specifically in the case of Fe-Al, the combined experimental study supported by theoretical simulations identified round/oval droplets of the disordered Fe-Al phase formed at the expense of diminishing amount of ordered Fe3Al phase.…”

Section: Introductionmentioning

confidence: 99%

Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study

et al. 2018

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Quantum-mechanical calculations are applied to examine magnetic and electronic properties of phases appearing in binary Fe-Al-based nanocomposites. The calculations are carried out using the Vienna Ab-initio Simulation Package which implements density functional theory and generalized gradient approximation. The focus is on a disordered solid solution with 18.75 at. % Al in body-centered-cubic ferromagnetic iron, so-called α-phase, and an ordered intermetallic compound Fe3Al with the D03 structure. In order to reveal the impact of the actual atomic distribution in the disordered Fe-Al α-phase three different special quasi-random structures with or without the 1st and/or 2nd nearest-neighbor Al-Al pairs are used. According to our calculations, energy decreases when eliminating the 1st and 2nd nearest neighbor Al-Al pairs. On the other hand, the local magnetic moments of the Fe atoms decrease with Al concentration in the 1st coordination sphere and increase if the concentration of Al atoms increases in the 2nd one. Furthermore, when simulating Fe-Al/Fe3Al nanocomposites (superlattices), changes of local magnetic moments of the Fe atoms up to 0.5 sans-serifμnormalB are predicted. These changes very sensitively depend on both the distribution of atoms and the crystallographic orientation of the interfaces.

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“…Both types were found separating partials of superdislocations in Fe-Al alloys [70][71][72]. Other findings related to APBs may be found, for example, in papers [73][74][75][76][77].…”

Section: Introductionmentioning

confidence: 62%

The Impact of Vibrational Entropy on the Segregation of Cu to Antiphase Boundaries in Fe3Al

2021

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We performed a quantum mechanical study of segregation of Cu atoms toward antiphase boundaries (APBs) in Fe3Al. The computed concentration of Cu atoms was 3.125 at %. The APBs have been characterized by a shift of the lattice along the ⟨001⟩ crystallographic direction. The APB energy turns out to be lower for Cu atoms located directly at the APB interfaces and we found that it is equal to 84 mJ/m2. Both Cu atoms (as point defects) and APBs (as extended defects) have their specific impact on local magnetic moments of Fe atoms (mostly reduction of the magnitude). Their combined impact was found to be not just a simple sum of the effects of each of the defect types. The Cu atoms are predicted to segregate toward the studied APBs, but the related energy gain is very small and amounts to only 4 meV per Cu atom. We have also performed phonon calculations and found all studied states with different atomic configurations mechanically stable without any soft phonon modes. The band gap in phonon frequencies of Fe3Al is barely affected by Cu substituents but reduced by APBs. The phonon contributions to segregation-related energy changes are significant, ranging from a decrease by 16% at T = 0 K to an increase by 17% at T = 400 K (changes with respect to the segregation-related energy difference between static lattices). Importantly, we have also examined the differences in the phonon entropy and phonon energy induced by the Cu segregation and showed their strongly nonlinear trends.

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The Formation and Dynamic Evolution of Antiphase Domain Boundary in FeAl Alloy: Computational Simulation in Atomic Scale

Cited by 11 publications

References 50 publications

A Quantum–Mechanical Study of Clean and Cr–Segregated Antiphase Boundaries in Fe3Al

A Quantum–Mechanical Study of Clean and Cr–Segregated Antiphase Boundaries in Fe3Al

Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study

The Impact of Vibrational Entropy on the Segregation of Cu to Antiphase Boundaries in Fe3Al

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