Crystal Defects Research Articles

Control spin–orbit coupling through changing the crystal structure of the metal halide perovskites

Metal halide perovskites (MHPs) have attracted wide interest in spintronics. In addition, they also perform various spin–orbit coupling (SOC) strength due to their complex crystal structures. The control of SOC strength has been an increasingly prevalent topic for the manipulation of the spin degree in spintronic devices. Here, we fabricate MAPbI3 films possessing cubic crystal phase and tetragonal crystal phase with Pb vacancies. Circular photogalvanic effect (CPGE) measurements indicate that CN, representing the difference between right and left circularly polarized photocurrents, of the tetragonal structure with Pb vacancies (CN = 0.6316) is almost three orders of magnitude larger than that of the cubic structure (CN = 0.0009). Combining with the density functional theory calculations, we confirm that the strength of SOC generating the CPGE could be tuned by crystal phases of MAPbI3, and the existence of Pb vacancies could remarkably enhance the spin splitting of the band structure. Our finding provides a possible way for clarifying various puzzling SOC performances in MHPs and paves the way for spintronic device applications and circularly polarized photoelectric detectors by controlling the crystal phases and defects.

Reduction of Structural Defects in the GaSb Buffer Layer on (001) GaP/Si for High Performance InGaSb/GaSb Quantum Well Light-Emitting Diodes.

Monolithic integration of GaSb-based optoelectronic devices on Si is a promising approach for achieving a low-cost, compact, and scalable infrared photonics platform. While tremendous efforts have been put into reducing dislocation densities by using various defect filter layers, exploring other types of extended crystal defects that can exist on GaSb/Si buffers has largely been neglected. Here, we show that GaSb growth on Si generates a high density of micro-twin (MT) defects as well as threading dislocations (TDs) to accommodate the extremely large misfit between GaSb and Si. We found that a 250 nm AlSb single insertion layer is more effective than AlSb/GaSb strained superlattices in reducing both types of defects, resulting in a 4× and 13× reduction in TD density and MT density, respectively, compared with a reference sample with no defect filter layer. InGaSb quantum well light-emitting diodes were grown on the GaSb/Si templates, and the effect of TD density and MT density on their performance was studied. This work shows the importance of using appropriate defect filter layers for high performance GaSb-based optoelectronic devices on standard on-axis (001) Si via direct epitaxial growth.

Wide-velocity range high-energy plasma sprayed yttria-stabilized zirconia thermal barrier coating — Part II: Structural defects and thermal-bonding properties

Traditional porous plasma-sprayed YSZ thermal barrier coatings (TBCs) present an inverse relationship between bonding strength and thermal insulation properties; achieving the synergistic improvement of both properties is a huge challenge for current plasma spraying methods. To address this challenge, in this work, we focus on regulating the structural defects of the TBCs by modifying the melting and in-flight behavior of plasma-spray particles. Dual-modal subsonic and novel multi-modal supersonic coatings were fabricated. The results suggested that the multi-modal structure of the supersonic coating with a defect content of approximately 13 % exhibited the highest tensile bonding strength (~74 MPa) and the lowest thermal conductivity (0.75–0.80 W∙m−1∙K−1 from 200 °C to 1000 °C). The high bonding strength was attributed to the epitaxial growth and mechanical interlocking of submicron−/nano-grains, whereas the low thermal conductivity came from the coexistence of an overlapping distribution of submicron-sized splats, discontinuous interfaces, and high-density crystal defects. Due to the competitive sintering of finer unmelted particles and recrystallization zones, the supersonic coating exhibited superior thermal insulation. Therefore, supersonic coating is considered as good candidates for high-performance TBCs.

Study on the characteristics of Si-doped diamond synthesized by different iron-based catalyst systems under high temperature and pressure

This article investigates the effects of different iron based catalysts on the morphology and quality characteristics of diamond single crystals synthesized in high-temperature and high-pressure environments. The results indicated that incorporating silicon impurities led to defects in diamond crystals, increased internal stress in the lattice, and decreased crystal quality. In addition, there are also differences in the synthesis of silicon doped diamonds under different iron based catalyst systems. This manuscript uses optical microscopy, scanning electron microscopy and Raman spectroscopy to characterize diamond crystals, exploring the influence of catalyst differences on the structure of silicon-doped diamonds. At the same time, simulation analysis was conducted on the convective field of the catalyst in the diamond synthesis chamber, and the convective field characteristics of silicon doped diamond growth under different iron based catalysts were established. The simulation results are consistent with the synthesis experimental work. This work provides a new approach to improve the quality of silicon doped diamond single crystals.

Effect of temperature, pressure, crystal defect types, and densities on the mechanical behavior of tungsten under tensile deformation: A molecular dynamics simulation study

The mechanical behavior of tungsten under tensile deformation was investigated using molecular dynamics simulations, with a focus on the effects of temperature, pressure, crystal defect types, and densities. Single vacancies, spherical voids, and self-interstitials were studied at concentrations ranging from 0.1% to 2%. The Common neighbor analysis reveals that the crystal structure underwent a phase transition from the body-centered cubic to the face-centered cubic structure at increasing levels of applied strain, followed by the formation of a disordered phase. Increasing temperature reduced the mechanical properties of tungsten, including yield strength, yield strain, modulus of elasticity, and ultimate tensile stress, possibly due to the activation of dislocation nucleation and propagation, resulting in the formation of dislocation loops. Increasing pressure enhanced the mechanical properties of tungsten, with the formation of dislocation loops occurring at much lower strains at higher pressures. All mechanical parameters decreased with increasing defect density, with self-interstitial defects having a more severe effect than single vacancies and spherical voids. The number and length of dislocation loops also increased with increasing defect density. Temperature and pressure had varying effects on the stress–strain curve of tungsten with different defect types and densities, with increasing pressure generally enhancing its mechanical behavior and increasing temperature decreasing it. These findings provide valuable insights into the design and development of tungsten-based materials with enhanced mechanical properties.

Fabricating Pt0-acid synergy in Pt/Beta phenol hydrodeoxygenation catalysts via a surface modification strategy of Beta molecular sieves

As for metal/zeolite supported phenol hydrodeoxygenation catalysts, it is important to improve the dispersion of metallic sites and build synergistic relationship between metallic and acid sites. The current research proposes a surface modification strategy by introducing CTAB in the NaOH etching of Beta. CTAB interacts with crystal defects to inhibit excessive crystal destruction. Aluminum atoms are protected from being removed and acid sites are reserved. Generated silicon hydroxyl groups anchor Pt0 particles. Pt0 particles are spatial resisted on the internal surface of catalysts to activate C–O bonds of phenol. Preserved acid sites provide reactive sites for dehydration reaction of cyclohexanol on the external surface of Pt/Beta-H. The high phenol conversion (i.e., 92.26 %) and cyclohexane yield (i.e., 7.18 %) were obtained at 80 °C due to the functional synergistic effect between acid and Pt0 sites. Proposed surface modification strategy proposes references for the structure design and development of efficient phenolics hydrodeoxygenation catalysts.

Clumped isotope reordering kinetics in strontianite and witherite: Experiments and first-principles simulations

The carbonate clumped isotope (∆47) thermometer is a powerful tool for temperature reconstruction based on the thermodynamical 13C—18O bonding preference. Accurate interpretation of temperatures requires preservation of original carbonate ∆47 signatures, which are susceptible to resetting at elevated temperatures during burial. Kinetic models of carbonate 13C—18O bond reordering derived from experimental studies constrain the evaluation of ∆47 preservation and the reconstruction of thermal histories and initial temperatures for reordered carbonates. However, application of these models to different carbonates is limited because kinetic parameters vary with materials and are believed to be affected by factors such as crystal structure, cation, trace element composition, crystal defects, and internal water whose roles in reordering are still not well-understood. Here we present reordering data for strontianite and witherite from heating experiments and evaluate the effects of crystal structure, cation chemistry, cation vacancy and substitution, and internal water on reordering using constrained ab-initio molecular dynamics (cAIMD) simulations. We show that strontianite and witherite reorder significantly faster than other carbonates. Comparing experimental studies yields the following reordering rate sequence: strontianite > witherite > aragonite > calcite > dolomite. The general trend in Arrhenius activation energy for reordering is strontianite < witherite < aragonite < dolomite < calcite (with calcite values based on the average of individual materials). Our cAIMD simulations reveal a similar trend in free energy of activation for oxygen exchange in these carbonates. We suggest that orthorhombic carbonates are more susceptible to reordering than trigonal carbonates because of the shorter distance between carbonate groups and because the weaker M—O interaction in orthorhombic carbonates reduces the structural distortion and the energy cost during transition state formation. For carbonates sharing the same structure, the weak M—O bonding can be compensated by a large unit cell volume, leading to a non-systematic relationship between the free energy of activation and the cation radius. In simulations with lattice-bound water, the free energy of activation is greatly reduced compared with cation vacancy and substitution. The influence of fluid inclusions on measured reordering rates depends on the fraction of carbonates that can exchange with water as suggested by strontianite δ¹⁸O data. Our results serve as a starting point for a more sophisticated but flexible kinetic model containing material-specific factors (e.g., substituted ions, structure water, etc.) for reordering in abiotic and biotic carbonates.

Structure characteristics and adsorption performance of graphene oxide prepared by spent carbon cathode-an ultra-low temperature graphitized carbon material.

Spent carbon cathode (SCC) is a hazardous waste from the aluminum electrolysis industry. It is commonly used as a carbon source in the current disposal and recovery strategies, such as combustion, or as a reductant for smelting. The novelty of this study is to propose a strategy for recycling SCC as a graphite resource and to investigate the unique structural characteristics and adsorption properties of graphene oxide produced from this low temperature graphitized carbon. The adsorption kinetics and isotherms of SCC-GO on methylene blue (MB) were studied and compared with the GO prepared from natural flake graphite (NFG) and artificial graphite (AG). The results show that SCC-GO exhibits the highest adsorption rate and adsorption capacity (647.83 mg/g) for MB, which is much higher than NFG-GO (451.22 mg/g) and AG-GO (533.12 mg/g). The analysis of the spectroscopy and morphology confirmed that SCC-GO has a high degree of crystal defects, oxidation, and surface wrinkle. Overall, this study reveals the unique structure of SCC-GO and highlights its significant scientific and application potential as an ultra-low temperature graphitized carbon. This research is also significant for recycling aluminum electrolytic cathode solid waste in the form of a graphite source.

Synergistic effect of B[sbnd]Nb co-modified to achieve crystal structure and interface tuning for Ni-rich cathode

Nickel-rich cathode materials play a pivotal role in the functioning of lithium-ion batteries, but their crystal structure defects and surface side reactions significantly affect battery performance. This has slowed down the commercialization process of nickel-rich cathodes. To remedy these problems, a new strategy utilizing B and Nb for crystal structure and interface control of LiNi0.8Co0.1Mn0.1O2 (NCM811) is proposed in this study. The BNb modified cathode exhibits strong radial orientation and exposes a large number of active (003) lattice plane on the particle surface. This structural control reduces micro-cracks and accelerates lithium-ion diffusion kinetics. Additionally, the LiNbO3 coating effectively avoids immediate contact between secondary particles and the electrolyte, greatly alleviating side reactions. Consequently, the optimal cathode B-NCM@LNO5 modified cathode maintains a capacity retention of 86.71% after 200 cycles at 1 C, outperforming the original material (76.11% retention). Meanwhile, it demonstrates attractive rate capability of 158.4 mAhg−1 under 5 C. This research provides valuable insights for addressing anisotropic strain and interface compatibility issues in nickel-rich cathodes.

New Insight into Elastic Mechanical Properties and Anisotropies of Crystal Defect α-Quartz from DFT Calculation.

To reveal the cleavage mechanism of α-quartz in the grinding process of nonferrous metal ores, mechanical and charge properties of α-quartz crystals are investigated using the density functional theory. Based on the elastic constant matrix, the bulk and shear moduli were calculated before and after the α-quartz with oxygen atom defects. The results show that the ratios of bulk and shear moduli (B/G) were 0.87 and 0.95, respectively, which indicated that at the same stress level, it was easier to fracture without O-vacancy defects than with O-vacancy defects. The mapping surfaces indicated that the O-vacancy defect increased the bulk-, shear-, and Young's moduli, and Poisson ratio while decreasing the hardness. The anisotropy index (AL and AU) was calculated which illustrated that the O-vacancy can result in an increased anisotropy; meanwhile, the bulk anisotropy index (AB) increased strongly about two times. The anisotropy analysis shows the dominance crystal cleavage of the (011) plane in the shear stress and the dominance crystal cleavage of the (111) plane in the normal stress. The electron localization function α-quartz show that the O-vacancy defect can decrease the Si-Si length from 3.703 to 2.442 Å, which indicated that the O-vacancy formed the new covalent bonds between silicon atoms. Our work provided a systematic approach containing the mechanical, anisotropic, and electronic properties of mineral crystals to explain the cleavage behavior of crystals.

Influence of cooling rate on microstructure and defect evolution in GaAs during solidification

The fabrication of high-quality GaAs crystals is essential to approach optimal performance in optoelectronic and microelectronic devices. In this study, a molecular dynamics simulation study was conducted for the solidification of liquid GaAs at three cooling rates (1010 K s−1, 1011 K s−1, and 1012 K s−1) at 300 K. The structural evolution in terms of crystal structure and defect formation in GaAs was thoroughly investigated using pair distribution function, average atomic energy, the largest standard cluster analysis, and visualization techniques. The results showed that the cooling rate of 1010 K s−1 led to the development of the best crystal quality with ease of eutectic twin grain boundary coherent twin boundary formation. Increasing the cooling rates to 1011 K s−1 and 1012 K s−1 resulted in the amorphous structure. Both high and low cooling rates profoundly affected the formation of As8 structure, but a maximum amount of 2.2% of As8 crystal structure was formed at a cooling rate of 1011 K s−1. The reduction in cooling rate to 1010 K s−1 induced the formation of numerous Schottky and Frenkel types of partial dislocations in the GaAs system. Results of this study can serve as potential guidelines to the theory of crystal growth and may be implemented in the fabrication of high-quality GaAs crystals for optimal device performance.

Crystallization Enhancement and Ionic Defect Passivation in Wide‐Bandgap Perovskite for Efficient and Stable All‐Perovskite Tandem Solar Cells

AbstractBy integrating wide‐bandgap (WBG) and narrow‐bandgap perovskites, monolithic all‐perovskite tandem solar cells have garnered significant attention as a prospective strategy for surpassing the efficiency limits of single‐junction cells. However, the WBG subcells, which significantly impact the performance and operational stability of all‐perovskite tandem solar cells, face notable challenges associated with pronounced nonradiative recombination losses and limited film photostability. Here, an efficient method is reported by adding potassium hypophosphite into the perovskite precursor solution to simultaneously regulate crystallization and passivate ionic defects in WBG perovskites. This approach results in high‐quality perovskite films and significantly improves the performance and photostability of WBG perovskite solar cells. The single‐junction devices with a 1.79 eV bandgap achieve a champion power conversion efficiency (PCE) of 20.06% with an open‐circuit voltage of 1.32 V. The devices retain ≈96% of their initial PCE following 913 h of continuous AM 1.5 G illumination. With these WBG perovskite subcells, monolithic all‐perovskite tandem solar cells are fabricated with an efficiency of 26.08%.

Diffusion and reaction behavior of palladium coating and copper matrix prepared using a halogen-free direct coating process

Herein, a palladium-coated copper wire was prepared using a halogen-free direct coating process, and the effects of the coating temperature on the morphology of the palladium coating and the mechanical properties of the wire were studied. The structural characteristics of the coating and copper matrix as well as the diffusion, reaction, and bonding characteristics of the elements at the copper–palladium interface were investigated. Results show that the deposition rate of palladium and the aggregation of palladium grains were accelerated with increasing coating temperature, promoting the formation of large palladium particles on the surface of the palladium-coated copper wire. The strength of the coated wire decreases and the elongation increases with increasing coating temperature. At 400 °C, the thickness of the coating was approximately 51 nm coating, consisting of approximately 4 nm nanocrystals. The improvement in plasticity was attributed to the distortionless recrystallized subgrain nucleus formed by the cell structure comprising dislocation tangles in the copper matrix, which reduces the matrix dislocation density. Positive and negative edge dislocations were present in the coating, and the two dislocation lines of the edge dislocation dipole offset each other. Numerous crystal defects were found in the copper–palladium bonding interface zone. Moreover, copper unidirectionally diffuses into the palladium coating, forming the intermetallic-compound CuPd in the interface bonding zone. Furthermore, the formation of twins was caused by the change in the stacking order of atoms due to the stacking fault occurring on the crystal surface, and the thickness of the diffusion zone was approximately 9 nm.

Effect of Al–Ti–B master alloy on microstructure and properties of aluminum-air battery anode materials

This study investigates the effects of Al–5Ti–B master alloy addition on the electrochemical properties and discharge performance of commercial pure aluminum (1060Al) in 4 M NaOH solution. The results show that the coarse branch-like α-Al grains are transformed into finer and smaller equiaxed grains, and the iron-rich phase are changed from long rod-like to small spherical grains. TiB2 particles introduce more heterogeneous nucleation sites in the α-Al crystals, resulting in an increased amount of grain boundaries in the aluminum matrix. There are more crystal defects at the grain boundaries than in the interior of α-Al grains, which provids more channels and energy for the reactions. This significantly increases the electrochemical activity of the aluminum alloy, causing the negative shifts for both the open circuit potential and the corrosion potential. The reduction in the size and change in the morphology of the iron-rich phase decreased the contact area between the iron-rich phase and the aluminum matrix, weakening the galvanic action between them. Meanwhile, the refinement of the α-Al grains decreased the potential difference between the interior and exterior of the grains, resulting in a reduction in the material corrosion current and an improvement in its corrosion resistance. Therefore, compared to the method of adding high hydrogen evolution potential elements to suppress hydrogen evolution reaction, the refinement of α-Al grains and the changes in the size and morphology of iron-rich phases due to the presence of TiB2 particles are the main reasons for improving the corrosion resistance and discharge performance of aluminum-air batteries in NaOH solution.

Enhanced CO2 adsorption performance by crystal defect method of multi-level pore Mg-MOF-74 using organic acids

Metal-organic frameworks (MOFs) are popular crystalline materials owing to their high porosity, tunable pore structure, and large surface area. By introducing a carboxylic acid to compete with 2,5-dihydroxyterephthalic acid for magnesium ions in solution, a crystal defect method was used to prepare multi-level pore Mg-MOF-74 with an unregular framework structure of Mg-MOF-74 in this paper. In the prepared samples, the adsorption amounts varied in descending order with various carboxylic acid species: Mg-MOF-74-Propionic acid (37.95 cm3/g STP) > Mg-MOF-74 (15.46 cm3/g STP) > Mg-MOF-74-Acetic acid (9.19 cm3/g STP) > Mg-MOF-74-Formic acid (7.81 cm3/g STP). At 1.5 kPa, the CO2 adsorption of 2,5-dihydroxyterephthalic acid and propionic acid with a ratio of 2:1 can reach 2.78 cm3/g STP (standard temperature and pressure) with the comparison to 0.47 cm3/g STP of pristine Mg-MOF-74. Under atmospheric pressure, the adsorption capacity of modified Mg-MOF-74 can reach 37.95 cm3/g STP, equivalent to 2.45 times of the original Mg-MOF-74.

The ions storage mechanism of capacitive-faradic coupling effect for pseudo-intercalation electrode MnO2

As one of the most promising faradic intercalation electrode materials, manganese dioxide (MnO2) has broad prospects in capacitive deionization for heavy metal removal. However, there are differences in capacitive deionization kinetics of MnO2 with different crystal structures, and the capacitive and faradic multi-process coupling mechanism are still unclear, which limits the optimization and development of these pseudo-intercalation electrodes. Here, we propose the potential ions storage routes involved into the capacitive and faradic coupling behavior and quantitatively analyze the evolution laws of heavy metal Cd2+ with respect to different crystal-structured MnO2 (α, β and δ). Mediated by the released electron from the cathode, Mn4+/Mn3+ faraday reaction on the MnO2 generates a large amount of surface faradic chemical charge (Mn-OH/Mn-O-), thereby driving the surface faradic storage of Cd2+ ions (28 %∼47 %). This finding breaks the traditional recognition that the pseudocapacitive deionization of MnO2 is dominated only tunnel pseudo-intercalation (14 ∼ 54 % in this study) and surface capacitive progress (12 ∼ 34 % in this study). Additionally, the fixed chemical-charge-controlled storage derived from crystal surface defect also contributed 4 ∼ 8 % to the total. Mn-O bond length is key to determine the tunnel intercalation capacity and the electron transfer ability along Mn4+-O-Mn3+ path to generates Mn4+/Mn3+ faradic charge, thus the surface faradic chemical-charge-controlled storage (β > α > δ) and pseudo-intercalation storage (δ > α > β) showed a potential mutual restriction effect. In this study, the electrochemical behavior of heavy metal ions and charge transfer mechanism at the interface of the MnO2 electrode were effectively clarified by combining the theoretical model and electrochemical analysis, which provided a new idea for expanding the understanding of the multiple ion storage processes coupling mechanism of intercalation materials and forming the regulation strategy for efficient capacitive coupled with faradic electrochemical deionization electrode materials.

Indirect effect of elevated temperature on radiation shielding competence through modulations of crystals' intrinsic tetrahedral parameters: A case study of berlinite, SiO2-type AlPO4

This paper investigates the indirect influence of elevated temperature on the radiation protections competence of berlinite (SiO2-type AlPO4) by examining the modulations of its intrinsic tetrahedral parameters. The study focuses on the temperature-dependent changes in the crystal structure of berlinite and their influence on its radiation attenuation properties. The lattice parameter a, and c, c/a ratio, unit cell volume (Vc), atomic packing factor (APF), and other factors such as the atomic arrangement, atomic interactions, and crystal defects are analyzed in relation to the MAC and LAC. The calculations are performed for berlinite AlPO4 samples prepared at temperatures ranging from 25 °C to 631 °C. The results reveal that the LAC values of berlinite AlPO4 are changed from 14.65 to 15.39 cm−1, indicating stable linear attenuation properties across the temperature range. The lattice parameters, Vc, and APF exhibit linear relationships with the LAC values, suggesting their significance in determining the radiation attenuation capabilities.

Enzyme‐Engineered Metal‐Organic Frameworks for the Construction of Organophosphorus Pesticide Biosensor

AbstractRational immobilization of fragile enzymes on a scaffold is an efficient protocol to achieve robust biocatalyst, yet the construction remains challenging due to the trade‐off between enzyme activity and framework environment. Herein, an enzyme‐engineered assembly strategy enabling the in situ fusion of acetylcholinesterase (AChE) into Zn‐based metal‐organic frameworks (Zn‐MOF‐74) during the rapid nucleation and crystal defect growth process, is demonstrated. The Zn‐MOF‐74 composites can offer a hydrophilic framework microenvironment for maintaining the biological state of AChE, with flower‐like porous structure that allows for boosting the mass transfer process of substrates and products. Impressively, the apparent activity of AChE can be well maintained 90% after encapsulation, and the AChE@Zn‐MOF‐74 composites produced excellent stability in inhospitable environments. Given the structural integration, a robust AChE@Zn‐MOF‐74‐based biosensor is constructed for the sensitive detection of chlorpyrifos (organophosphorus pesticides) with a detection limit of 1.0 ng mL−1, enabling the monitoring of pesticide degradation extent in the water body. This study is anticipated to offer valuable insight into understanding the structure‐activity relationship of enzyme@MOF to encourage applications in the construction of robust biosensors for precision agriculture.

ZnO Deposition on Silicon and Porous Silicon Substrate via Radio Frequency Magnetron Sputtering

Nanostructured Zinc Oxide (ZnO) was deposited on silicon (c-Si) and macroporous silicon (m-PS) using a radio frequency (RF) reactive magnetron sputtering technique. Two RF powers of 60 and 80 W were selected for ZnO deposition on the substrates. Furthermore, the c-Si and m-PS substrate temperatures were kept at 500 and 800 °C, respectively. The morphological, structural, and optical characteristics of the samples were studied using scanning electron microscopy (SEM), an X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The SEM images revealed the formation of ZnO nanorods on the c-Si and ZnO nanostructures constituted by the assembly of nanorods. It has been found that the increasing RF sputtering power caused the rise in the residual stress. In addition, the increase in the deposition temperature caused an improvement in the arrangement of the crystals, which was attributed to the decrease in crystal defects.

Understanding the formation mechanisms and stability of the Anti-Phase boundaries (APBs) in Al-Fe B2

Al-Fe B2 alloys (with ordered Body Centered Cubic lattice, BCC) are an example of high strength, brittle materials containing multiple crystal defects, such as dislocations, vacancies and Anti-Phase Boundaries (APB). Although latter were reported to play a major role in mechanisms influencing mechanical properties, reports on formation mechanisms of APBs are limited and contradictory. To close this gap in understanding, FexAl1−x alloys were studied in Transmission Electron Microscope (TEM). Changing the Long-Range Order, η, parameter (calculated using statistical thermodynamics according to the composition of the samples) from 1 (50 at% Fe, i.e., perfect order) to η = 0.53 (68 at% Fe) caused an increase in density of the <111> type dislocations. At η = 0.53 – APBs have started to form. These experimental results were in-line with Density Functional Theory calculations. Since above 68 at% Fe, D03-type structure has also formed in the B2 grains, its role in formation of the APBs was assessed. It was determined that these two phenomena are not related. Therefore, outcomes of current research are of general applicability to other B2 structures regardless existence of D03 or lack of such additional ordering. Furthermore, driven conclusions have a potential to impact the BCC-based High Entropy Alloys, where B2 is the matrix.