Gap Air Research Articles

A systematic investigation of chromium and vanadium impurities in a Janus Ga2SO monolayer towards spintronic applications.

Transition metals (TMs) have been employed as efficient sources of magnetism in non-magnetic two-dimensional (2D) materials. In this work, doping with chromium (Cr) and vanadium (V) is proposed to induce feature-rich electronic and magnetic properties in a Janus Ga2SO monolayer towards spintronic applications. The Ga2SO monolayer is a 2D semiconductor material with an energy gap of 1.30 (2.12) eV obtained from PBE(HSE06)-based calculations. Considering the structural asymmetry, different vacancy and doping sites are considered. A single Ga vacancy and pair of Ga vacancies magnetize the monolayer with total magnetic moments between 0.69 and 3.13μB, where the half-metallic nature is induced by the single Ga1 vacancy (that bound to the S atom). In these cases, the magnetism is originated mainly from S and O atoms closest to the vacancy sites. Depending on the doping site, either half-metallicity or diluted magnetic semiconductor natures are obtained by doping with Cr and V atoms with total magnetic moments of 3.00 and 2.00μB, respectively. Herein, 3d TM impurities produce mainly the system magnetism. When substituting a pair of Ga atoms, TM atoms exhibit the antiparallel spin alignment to follow the Pauli exclusion principle, retaining the novel electronic characteristics induced by a single TM dopant. Except for the case of doping with a pair of V atoms, total magnetic moments of 2.00 and 1.00μB are obtained by doping with a pair or Cr atoms and Cr/V co-doping, respectively. The non-zero magnetic moment is derived from the different interactions of each TM atom with its neighboring atoms, which will also be studied by Bader charge analysis. Our results introduce new promising 2D spintronic candidates, which are made by structural modifications at Ga sites of a non-magnetic Janus Ga2SO monolayer.

AdaptMLLM: Fine-Tuning Multilingual Language Models on Low-Resource Languages with Integrated LLM Playgrounds

The advent of Multilingual Language Models (MLLMs) and Large Language Models (LLMs) has spawned innovation in many areas of natural language processing. Despite the exciting potential of this technology, its impact on developing high-quality Machine Translation (MT) outputs for low-resource languages remains relatively under-explored. Furthermore, an open-source application, dedicated to both fine-tuning MLLMs and managing the complete MT workflow for low-resources languages, remains unavailable. We aim to address these imbalances through the development of adaptMLLM, which streamlines all processes involved in the fine-tuning of MLLMs for MT. This open-source application is tailored for developers, translators, and users who are engaged in MT. It is particularly useful for newcomers to the field, as it significantly streamlines the configuration of the development environment. An intuitive interface allows for easy customisation of hyperparameters, and the application offers a range of metrics for model evaluation and the capability to deploy models as a translation service directly within the application. As a multilingual tool, we used adaptMLLM to fine-tune models for two low-resource language pairs: English to Irish (EN↔ GA) and English to Marathi (EN↔MR). Compared with baselines from the LoResMT2021 Shared Task, the adaptMLLM system demonstrated significant improvements. In the EN→GA direction, an improvement of 5.2 BLEU points was observed and an increase of 40.5 BLEU points was recorded in the GA→EN direction representing relative improvements of 14% and 117%, respectively. Significant improvements in the translation performance of the EN↔MR pair were also observed notably in the MR→EN direction with an increase of 21.3 BLEU points which corresponds to a relative improvement of 68%. Finally, a fine-grained human evaluation of the MLLM output on the EN→GA pair was conducted using the Multidimensional Quality Metrics and Scalar Quality Metrics error taxonomies. The application and models are freely available.

Magnetostrictive improvement in Er-doped biodegradable Fe81Ga19 alloys manufactured by selective laser melting

In this study, rare earth Er was introduced into magnetostrictive Fe–Ga alloys by selective laser melting (SLM) technique for the first time in order to tailor the microstructure and thereby the magnetostrictive properties. The results showed that the rapid solidification of SLM process not only retained the disorder phases but also promoted the solid solution of partial Er into Fe–Ga matrix which increased the lattice parameters. Moreover, the rest of Er distributed at the grain boundaries along the temperature gradient and prevented the lateral expansion of matrix grains, leading to columnar grains with preferred orientation in {100} direction. Consequently, the magnetostriction coefficient of the Er-doped Fe81Ga19 alloys was improved up to 92 ppm with an Er content of 0.6 at.%, representing a 40% enhancement compared to Fe81Ga19 alloy. But excessive Er resulted in the formation of GaEr intermetallic phase, which was adverse to Ga–Ga pair structure and magnetostriction. The Fe81Ga19Er0.6 alloy also presented acceptable cytocompatibility and slightly accelerated degradation due to the galvanic corrosion between Er phase and Fe–Ga matrix. These findings indicated the potential of the Er-doped Fe81Ga19 alloys prepared by SLM as future magnetostrictive implants in biology and medicine.

An Accurate Demodulation Method for Fiber-Optic Interferometric Sensors Based on the Expanded Free Spectral Range

We propose and demonstrate an accurate demodulation method for fiber-optic interferometric sensors (FOISs) by utilizing an expanded free spectral range (EFSR). Unlike conventional demodulation schemes, this method selects a pair of resonant wavelengths (peaks or dips) with an interval of multiple free spectral ranges (FSRs) to determine the optical path difference (OPD) of the FOIS. This demodulation method significantly improves the measurement accuracy of the FOIS while maintaining a fast processing speed. The feasibility of the proposed method is experimentally demonstrated by our recently developed fiber-optic piezometer using a 178- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -gap air extrinsic Fabry–Perot interferometer (EFPI). Liquid level measurement in the range of 0–90 cm with a step of 15 cm is conducted with this method, and the experimental results demonstrate improved performance in terms of linearity, standard error (SE), and resolution. The measurement resolution increases significantly from 8.57 to 1.48 cm when the EFSR orders vary from 1, 4, 8, 12, 16, to 20. To further validate the proposed method, the measurement in the range of 0–24 cm with a step of 4 cm is performed for comparison, and the resolution is exponentially improved from a failed state to as high as 0.41 cm. Furthermore, five sets of historical data are chosen to establish regression models, and the results are consistent with the rest 14 sets of measured data. The proposed demodulation method is precise, rapid, and versatile, which would be useful in the further development and application of FOISs.

Influences of Gap Flow on Air Resistance Acting on a Large Container Ship

In terms of speed lost and fuel consumed, wind loads are considered one of the main factors for large ship design, especially for container ships. Alongside water resistance, air resistance in strong wind conditions has a significant impact on the fuel efficiency and performance of container ships with large box-type bodies. This paper reports the effects of wind loads acting on a 20,000 TEU container ship carrying large numbers of deck containers using a commercial CFD software program (ANSYS Fluent V14.5 with RANS equation). A 1/255.3 scale model was used in this study to reveal the air resistance on the container ship configuration. The aerodynamic formations of the complex vortices, pressure, velocity contours, and streamlines, as well as the air forces acting on the container ship, are presented and discussed. The pressure distributions show that the gap air flows increase the stagnation pressure at the face side and decrease the pressure on the backside of each container gap through separate eddies. The difference in pressures created in the gaps contribute to the air resistance acting on the ship. It is confirmed that the use of side covers of deck containers to close the gap flows between container blocks can significantly reduce the air resistance for wind directions in the range of 30 to 60 degrees.

Oxygen mediated defect evolution in RF sputtered Ga2O3 thin films on p-Si substrate

Impact of oxygen concentration in governing the structural and optical properties of RF sputter Ga 2 O 3 thin film deposited on p-Si at 500 o C by controlling the oxygen flow rate (OFR) has been demonstrated in this work. To maintain the oxygen rich and oxygen poor condition, the argon (Ar) to oxygen (O 2 ) ratio systematically varied from 1:1, 1:2, to 1:0, 2:1 and, 3:1 respectively. Such OFR reliant change in crystalline quality of the grown Ga 2 O 3 thin film is investigated by X-ray Diffraction (XRD) study. The atomic force microscopy results further illustrate an increase in film roughness owing to the inevitable introducing of defects/ oxygen vacancy ( V O ) during deposition with higher OFR. The modification in material stoichiometry via generation of V O and defects in surplus of oxygen is further supported with XPS analysis. Moreover, a rising trend of optical bandgap (Eg) due to transformation from oxygen rich to oxygen poor condition was revealed by spectroscopic ellipsometery study and further correlated with the improved crystallinity of the film. A maximum Eg of 4.44 eV was obtained for the Ga 2 O 3 thin film deposited with 3:1 Ar to O 2 ratio. Finally, the photoluminescence (PL) investigation confirms a strong correlation between defects/ V O generation with OFR variation. Where, the decrease in blue band contribution in lower oxygen concentration was correlated with reduced Vo concentration via its active participation in gallium vacancy V Ga and Vo pair (V Ga +Vo) formation. Finally, the impact of OFR on the Ga 2 O 3 /Si heterojunction device property is also investigated by utilizing the current–voltage (I-V) measurements, which shows a superior device performance for film grown in oxygen poor condition owing to the presence of lower defect concentration, surface roughness, and interface states. • Oxygen mediated structural, chemical and optical transformation of Ga 2 O 3 thin film deposited on p-Si substrate at 500 o C temperature by RF sputtering. • Impact of oxygen extremes on the defect evolution of Ga 2 O 3 thin film by photoluminescence study. • The heterojunction properties of β-Ga 2 O 3 /Si are studied electrically and such heterojunctions exhibit relatively superior rectification properties. • 3:1 is the optimum Ar to O 2 ratio to achieve high quality, defect-free Ga 2 O 3 film on Si.

Intermetallic compounds RE 2Ga2Mg (RE = Tb–Tm, Lu) with Mo2B2Fe-type structure

Abstract The rare earth intermetallic compounds RE 2Ga2Mg with RE = Tb–Tm and Lu were synthesized from the elements in sealed tantalum ampoules in a high-frequency furnace. These rare earth-rich phases crystallize with the tetragonal Mo2B2Fe-type structure, space group P4/mbm and Z = 2. The polycrystalline samples were characterized through their Guinier powder patterns. The structures of Er2Ga2.092(1)Mg0.908(1), Tm2Ga2.037(1)Mg0.963(1) and Lu2Ga2.176(1)Mg0.824(1) have been refined from single crystal X-ray diffractometer data. The refinements revealed small homogeneity ranges (small degrees of Mg/Ga mixing on the 2a sites). The magnesium atoms show square planar coordination by Ga2 dumbbells (282 pm Mg–Ga and 257 pm Ga–Ga in the lutetium compound). Geometrically one can describe the RE 2Ga2Mg phases as 1:1 intergrowth structures of CsCl and AlB2-related slabs of compositions REMg and REGa2. From DFT based calculations, charge transfer from the rare earth and magnesium atoms towards gallium can be illustrated in electron localization function ELF slice planes showing strong localization around gallium in the basal plane as well as along the tetragonal c axis signaling Ga–Ga pair interactions. The site-projected density of states DOS and COOP data further quantify this observation. Temperature dependent magnetic susceptibility measurements show Pauli paramagnetism for Sc2Ga2Mg and Lu2Ga2Mg with low room temperature susceptibility values of 2.1(1) × 10−4 and 1.1(1) × 10−4 emu mol−1, respectively. Ho2Ga2Mg, Er2Ga2Mg and Tm2Ga2Mg are Curie-Weiss paramagnets with stable trivalent rare earth ground states. Antiferromagnetic ordering was detected below the Néel temperatures of T N = 18.6(1) (RE = Ho), 11.9(1) (RE = Er) and 6.4(1) K (RE = Tm). The three compounds show metamagnetic transitions in their 3 K magnetization isotherms. Tm2Ga2Mg exhibits a square loop behavior with small hysteresis.

Effect of Environmental Parameters on Streamer Discharge in Short Air Gap between Rod and Plate

Environmental meteorological parameters (temperature, humidity, air pressure, etc.) have an important impact on short gap streamer discharge. Based on the streamer theory and particle continuity equation of gas discharge, a short gap streamer discharge simulation model is established, and the influence of environmental parameters on the dynamic development process of streamer discharge is simulated and analyzed. The short gap air gap discharge characteristics were tested in a self-made gas discharge chamber. The results show that at low humidity (relative humidity &lt;80%), with the increase of humidity, the electron density of the streamer channel increases, the field strength of the streamer head increases, the streamer development speed speeds up, and the gap breakdown voltage decrease; At higher humidity (relative humidity &gt;80%), with the increase of humidity, the electron density of the streamer channel decreases, the field strength of the streamer head decreases, the development speed of the streamer slows down, and the gap breakdown voltage increase. With a decrease of gas pressure, the electron density of the streamer channel decreases, the field strength of the streamer head decreases, the development speed of the streamer increases, and the gap breakdown voltage decreases; The temperature change has little effect on the streamer development process.

Optimization of Design for Air Gap Sensor Using the Response Surface Methodology

In Hard Disk Drive (HDD) manufacturing, there is always a concern about the cutting defects that are caused by residual cutting chips. Only a small amount of 10 μm chips (act as the air gap) can cause the workpiece to tilt and shift from the correct position, and thus affect the dimension of the workpiece (mainly the Base HDD). For this reason, researchers adapted the adjustable micrometer as a simulation device that resembles the air gap for the design of the Air Gap Sensor Module. The design of experiments using response surface methodology will be studied to confirm the appropriate factors of the prototype. This study reports the optimization of the main factors that affect Air Gap Sensor Module condition: Air Nozzle Diameter 2.303 mm, Air Pressure 0.1 MPa, and Sampling Time 645 ms, which has a high square of the coefficient correlation (R-squared = 99.0%) with a close relationship between gap distance and air pressure. The relationship between these variables is mostly linear. The R-squared error percentage of actual value is less than 0.93% compared to predicted value. The mathematical model results and experimental values were consistent and able to predict response variables. The Air Gap Sensor Module can provide the measurement results in micron ccuracy and displays light and beep to confirm as acceptable or reject gap conditions with the uncertainty of measurement ± 0.001 mm.

Micro gap air discharge based on fractal theory

Micro-gap discharge is a form of gas discharge in which the discharge gap is on the order of sub-millimeters orless. To study the initial path of micro-gap discharge and the mechanism and law of particle density change during discharge, in this paper a micro-gap discharge experiment and discharge image acquisition device under atmospheric pressure is built and the COMSOL simulation software is used to simulate the electron density and space charge in the process of micro-gap air discharge. Furthermore, the MATLAB software is used to calculate the fractal dimension and probability development index of micro-gap discharge. The air discharge phenomena produced by applying positive DC voltage to needle tip at atmospheric pressure and room temperature with gap distance ranging from 50 μm to 150 μm are studied. It is found experimentally that there are twists and turns in the discharge channel, and the number of bifurcations in the discharge process with a short gap is less than that with a long gap. Observation of the micro-gap air discharge process with a gap of 100 μm under atmospheric pressure shows that the discharge process is divided into the following three processes: needle tip corona, corona breakdown streamer, and spark discharge channel. Based on the analyses of these experimental results, it can be concluded that the discharge mechanism follows Thomson's theory, supplemented by the streamer theory. The cathode secondary electron emission (including positive ions colliding with the cathode and photoelectron emission) and the space charge distortion electric field form a secondary electron avalanche to maintain the discharge together. The seed electrons formed by a small amount of space photoionization also form an electron avalanche under the action of the space charge distortion electric field. There are tortuous sections in the discharge channel, but the number of branches is small and the degree of tortuosity is low. Therefore, there are weak streamer forms. The discharge channel is tortuous and branched, but the number of bifurcations is relatively small, and the tortuousness is low. In addition, it is also found that a sheath is formed at the cathode, the distortion of electric field is 3–8 times that of original electric field, and the electron density reaches 2 × 10&lt;sup&gt;21&lt;/sup&gt; m&lt;sup&gt;–3&lt;/sup&gt; during discharge, obtained from the COMSOL simulation. Meanwhile, the fractal theory simulation is used to simulate the micro-gap discharge. In the process of research, the fractal dimension is found to be proportional to the voltage and the gap distance. When the probability development index &lt;i&gt;η&lt;/i&gt; = 1.18–1.3, the fractal dimension of the simulated discharge process is closer to the experimental result. The findings in this paper lay the foundation for further exploring the discharge theory of sub-micro- and nano-scaled gaps.

Unveiling the Different Physical Origins of Magnetic Anisotropy and Magnetoelasticity in Ga-Rich FeGa Thin Films

The aim of this work is to clarify how in-plane magnetic anisotropy and magnetoelasticity depend on the thickness of Ga-rich FeGa layers. Samples with an Fe72Ga28 composition were grown by sputtering in the ballistic regime in oblique incidence. Although for these growth conditions uniaxial magnetic anisotropy could be expected, in-plane anisotropy is only present when the sample thickness is above 100 nm. By means of differential X-ray absorption spectroscopy, we have determined the influence of both Ga pairs and tetragonal cell distortion on the evolution of the magnetic anisotropy with the increase of FeGa thickness. On the other hand, we have used the cantilever beam technique with capacitive detection to also determine the evolution of the magnetoelastic parameters with the thickness increase. In this case, experimental results can be understood considering the grain distribution. Therefore, the different physical origins for anisotropy and magnetoelasticity open up the possibility to independently tune these two characteristics in Ga-rich FeGa films.

Hydrogen passivation of iron-acceptor pairs in boron and gallium co-doped crystalline silicon

The hydrogen (H) passivation behaviors of iron-acceptor (Fe-Ac) pairs in boron and gallium co-doped Czochralski silicon are studied. H atoms introduced by a piranha solution followed by reverse bias annealing can fully passivate the electric activity of Fe–B and Fe–Ga pairs. However, the passivation effect can be partially deactivated when annealed in 80 °C–200 °C and be reactivated when annealed at 250 °C. The temperature of the highest failure fraction for passivated Fe–B and Fe–Ga pairs are 80 °C and 200 °C, respectively. A mechanism was given that H atoms released from the dissociation of acceptor-hydrogen pairs can reactivate the passivation.

Characterization and Assessment of a Novel Plate and Frame MD Module for Single Pass Wastewater Concentration-FEED Gap Air Gap Membrane Distillation.

Membrane distillation (MD) is an up and coming technology for concentration and separation on the verge of reaching commercialization. One of the remaining boundaries is the lack of available full-scale MD modules and systems suitable to meet the requirements of potential industrial applications. In this work a new type of feed gap air gap MD (FGAGMD) plate and frame module is introduced, designed and characterized with tap water and NaCl–H2O solution. The main feature of the new channel configuration is the separation of the heating and cooling channel from the feed channel, enabling a very high recovery ratio in a single pass. Key performance indicators (KPIs) such as flux, gained output ratio (GOR), recovery ratio and thermal efficiency are used to analyze the performance of the novel module concept within this work. A recovery rate of 93% was reached with tap water and between 32–53% with salt solutions ranging between 117 and 214 g NaCl/kg solution with this particular prototype module. Other than recovery ratio, the KPIs of the FGAGMD are similar to those of an air gap membrane distillation (AGMD) channel configuration. From the experimental results, furthermore, a new MD KPI was defined as the ratio of heating and cooling flow to feed flow. This RF ratio can be used for optimization of the module design and efficiency.

Local and Medium Range Order Influence on the Magnetic Behavior of Sputtered Ga-Rich FeGa Thin Films

We have investigated the influence of the growth power on the structural properties of Fe100–xGax (x ca. 29) films sputtered in the ballistic regime in the oblique incidence. By means of different structural characterizations, mainly X-ray diffraction and X-ray absorption spectroscopy, we have reached a deeper understanding about the influence of the local and medium range order on the magnetic behavior of Ga-rich FeGa thin films. On the one hand, the increase of the growth power reduces the crystallite size (medium order) that promotes the decrease of the coercive field of the layers. On the other hand, the growth power also determines the local order as it controls the formation of the A2, B2, and D03 structural phases. The increase of the uniaxial in-plane magnetic anisotropy with growth power has been correlated with the enhancement of both Ga pairs and a tetragonal distortion. The results presented in this work give more evidence about the magnetic anisotropy sources in Ga-rich FeGa alloys, and therefore, it helps to understand how to achieve a better control of the magnetic properties in this family of alloys.

Bulklike behavior of magnetoelasticity in epitaxial Fe1−xGax thin films

Bulk ${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}$ alloys present a strong sensitivity of the magnetostrictive properties with Ga content with maximum magnetostriction near $x=0.19$. Here, we present magnetoelastic coefficients measured by the cantilever method on ${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}$ thin films grown by molecular beam epitaxy on GaAs(001). We find that Ga-dependent magnetoelastic coefficients in nanometer thin films are comparable in magnitude to the respective bulk values. Moreover, we compare thin films with a tetragonal structure due to a slightly preferential alignment of Ga pairs along the growth direction with and a cubic structure. It turns out that magnetoelastic coefficients are unaffected by a preferential alignment of Ga pairs along the growth direction.

Effectiveness of Double Skin Façade in Controlling Indoor Air Temperature of Tropical Buildings

Double Skin Facade (DSF) application on buildings envelope in tropical area aims to decrease cooling load of buildings. Generally, the system is applied on building in an extreme outdoors air temperature, so it could achieve a comfortable air temperature for occupants. This paper discusses effectiveness to control indoor air temperature of some DSF factors such as; 1) air gap between DSF and building façade, 2) glass type. For these purposes, collect outdoor, indoor and air gap air temperatures, surface temperature of all glass surfaces and indoor-outdoor globe temperatures. The initial results show an optimum setting of air gap and glass type of the DSF, as well as some guidance on glass type selection for building surface and DSF.

Influence of Gap Air Flushing on Plasma Channel and Crater Geometry in Single Blasting Erosion Arc Discharge

Blasting erosion arc machining (BEAM) is a promising method for machining difficult-to-cut materials. In BEAM, high pressure inner flushing is implemented to increase machining efficiency in terms of material removal. However, effects of flushing on plasma arc evolution and material removal mechanism in BEAM are still unknown. In this research, air was blown to a single arc discharge as an alternative to water based dielectric in BEAM process. Using an ultra-fast four channel ICCD camera, influence of cross directional air jet on plasma channel development and crater formation was studied. Observation showed that plasma arc channel is obviously disturbed in presence of high speed air flushing. In other word, arc plasma column moves along the air flushing direction. Consequently, crater geometry and electrode wear will highly be influenced by air flushing in the gap. High speed air flushing increases molten metal flushed away from molten pool compare to the stationary air medium condition. This indicates that there is a decrease in recast layer on machined surface and as a result, volume of removed material will increase. Moreover, using high speed air flushing in single arc discharge decreases tool electrode wear volume significantly. Finally, based on the experimental results and theoretical analysis, high speed air flushing proves aerodynamic arc disturbing phenomenon during single arc discharge which is a potential evident to hydrodynamic arc breaking mechanism in BEAM.

Mixed guanine, adenine base quartets: possible roles of protons and metal ions in their stabilization

Structural variations of the well-known guanine quartet (G4) motif in nucleic acid structures, namely substitution of two guanine bases (G) by two adenine (A) nucleobases in mutual trans positions, are discussed and studied by density functional theory (DFT) methods. This work was initiated by three findings, namely (1) that GA mismatches are compatible with complementary pairing patterns in duplex-DNA structures and can, in principle, be extended to quartet structures, (2) that GA pairs can come in several variations, including with a N1 protonated adeninium moiety (AH), and (3) that cross-linking of the major donor sites of purine nucleobases (N1 and N7) by transition metal ions of linear coordination geometries produces planar purine quartets, as demonstrated by some of us in the past. Here, possible structures of mixed AGAG quartets both in the presence of protons and alkali metal ions are discussed, and in particular, the existence of a putative four-purine, two-metal motif.

Nuclear Magnetic Resonance Structure of an 8 × 8 Nucleotide RNA Internal Loop Flanked on Each Side by Three Watson-Crick Pairs and Comparison to Three-Dimensional Predictions.

The prediction of RNA three-dimensional structure from sequence alone has been a long-standing goal. High-resolution, experimentally determined structures of simple noncanonical pairings and motifs are critical to the development of prediction programs. Here, we present the nuclear magnetic resonance structure of the (5'CCAGAAACGGAUGGA)2 duplex, which contains an 8 × 8 nucleotide internal loop flanked by three Watson-Crick pairs on each side. The loop is comprised of a central 5'AC/3'CA nearest neighbor flanked by two 3RRs motifs, a known stable motif consisting of three consecutive sheared GA pairs. Hydrogen bonding patterns between base pairs in the loop, the all-atom root-mean-square deviation for the loop, and the deformation index were used to compare the structure to automated predictions by MC-sym, RNA FARFAR, and RNAComposer.

Effects of atomic arrangements on electronic structures of threading dislocations in III‐nitride alloy semiconductors: A first‐principles study

AbstractThe effects of atomic arrangements of group‐III elements on the electronic structures of threading dislocations in III‐nitride semiconductors are theoretically investigated on the basis of first‐principles calculations within the density functional theory. Our calculations for edge and screw dislocations in AlGaN and InGaN reveal that these dislocations induce localized electronic states in the energy gap. The analysis of wave functions reveals that the appearance of these electronic states originates from the Ga–Ga pair and N atoms, which constitute the dislocation core configuration. Furthermore, these states are found to be leading to electronic bands corresponding to indirect transition implying that these dislocation act as non‐radiative centers, consistent with the experimental results.