Single Vacancy Research Articles

[formula omitted] magnetism engineering in the low-buckled hexagonal SiS monolayer: A first-principles study

In this work, vacancy- and doped-induced magnetism engineering is investigated to functionalize the non-magnetic low-buckled hexagonal silicon sulfide (SiS) monolayer. This monolayer is an indirect gap semiconductor two-dimensional (2D) material with an energy gap of 2.20(3.02) eV obtained from the PBE(HSE06)-based calculations. Creating a single Si vacancy leads to a significant magnetization of SiS monolayer with the feature-rich half-metallic nature. Herein, a total magnetic moment of 1.89 μB is obtained and magnetic properties are produced mainly by S and Si atoms closest to the defect site. In contrast, single S vacancy preserves the non-magnetic nature inducing a band gap reduction of the order of 26.36%. n-type doping with P atom metalizes the monolayer, meanwhile As impurity leads to the emergence of the half-metallicity with a total magnetic moment of 1.00 μB. Similarly, this value is also obtained by p-doping using P and As atoms as dopants, where the diluted magnetic semiconductor nature is obtained. Moreover, doping with IA- (Na and K) and IIIA-group (Al and Ga) atoms is also proposed to engineer the magnetism in SiS monolayer. It is found that these impurities induce either half-metallic or diluted magnetic semiconductor behaviors with total magnetic moment between 0.99 and 1.00 μB. The electronic and magnetic properties are regulated mainly by the interactions between impurities and their neighbor S atoms, which modify the charge distribution in their outermost orbitals. In addition, the Bader charge analysis asserts that dopant atoms gain charge from the host monolayer when substituting S atom, meanwhile they act as charge loser — transferring charge to the host monolayer when doping at Si sublattice. The presented results may suggest efficient approaches to properly engineer SiS monolayer electronic and magnetic properties, making new 2D candidates for spintronic applications.

Interaction of Titanium Atoms with the Surface of Perfect and Defective Carbon Nanotubes

The dispersion of metal atoms over the surface of 1D and 2D carbon systems is the most affordable way to control their properties, which are attractive for many applications in electronics, power engineering, and catalysis. In this work, the features of the interaction of titanium atoms with the surface of carbon nanotubes, caused by various structural defects on these surfaces, were studied by first-principles computer simulation based on the density functional theory. Nanotubes (7, 7) and (11, 0) with similar diameters (≈1 nm) but different types of conductivity, metallic and semiconductor, respectively, were chosen for the study. Three types of defects were studied: a single vacancy, a double vacancy, and a topological defect. Two possible orientations of each type of defect relative to the tube axis were considered. We mainly used the basis of atomic-like orbitals (the SIESTA package) and in some test calculations also the basis of plane waves (the VASP package). Computational experiments have shown that the binding energy of Ti atoms with a defect-free nanotube is always lower than with defective ones, regardless of the used approximation for the exchange-correlation functional (LDA or GGA). The binding energies predicted in the LDA approximation are noticeably higher than in the GGA approximation (up to ~15% for the (7, 7) tube and up to ~50% for the (11, 0) tube). The strongest coupling occurs when the titanium atom is adsorbed on a nanotube with a single vacancy. The resulting configuration can be considered as a defect in the substitution of one carbon by a titanium atom.

Influence of mono‐ and bi‐vacancy doped alkaline‐earth metals on the optoelectronic properties of monolayer defective state MoTe2: A first‐principles study

AbstractThe effects of single‐vacancy and double‐vacancy doping with alkaline‐earth metals on the stability, electronic structure, charge transfer, and optical properties of molybdenum ditelluride in the monolayer defective state (MoTe2) have been investigated using first‐principles methods. It is found that the structure of the molybdenum ditelluride system is more stable after double Te vacancies, with direct band‐gap to indirect band‐gap transitions occurring in single Te vacancies and Mo vacancies, and semiconductor to quasi‐metal transitions occurring in double Mo vacancies. The binding energy in the defect state system of molybdenum ditelluride after vacancy defects is always negative, and the structure remains stable. In this paper, the most stable double Te vacancy state was selected for substitutional doping with alkaline‐earth metals, and the Be atoms were doped with the largest amount of morphology, and Ca atoms were doped with the most pronounced decrease in band gap value. The direct band‐gap semiconductor is maintained after doping with Be atoms. Doping with Mg, Sr and Ba changes the band‐gap from direct to indirect. The double Te defect state MoTe2 doped with Ca atoms has a tendency to transition to a quasi‐metal. Regarding photoelectric properties, the system is blue‐shifted on both the absorption and reflection peaks.

Alkali Silicates Codoped with NIR-Emitting RE (Nd3+ and Yb3+) Ions for Thermometry Applications.

In the present study, the synthesis of BaSrSiO4 co-doped Yb3+ and Nd3+ nanophosphors (NPs) was successfully achieved through the conventional sol-gel method, as confirmed by X-ray diffraction and SEM analysis, verifying the formation of pure NPs. The FTIR and Raman spectra analysis confirm the formation of silicates, as different modes and vibrations of Si-O and Si-O-Si were seen at 800-1000cm-1. The energy transfer (ET) mechanism between Nd3+ and Yb3+ ions was seen as the emission spectra showed a rise in intensity of one over another. PLE emission spectra showed transitions at 2F7/2-2F5/2 for Yb3+ and from 4F3/2 to (4I9/2, 4I11/2, and 4I13/2) for Nd3+ when excited at 785nm. All the samples record low activation energy, which shows that the rate of reaction will be higher in all the samples, and it will be highest for 1mol% Nd3+ and 1mol% Yb3+. An increasing value of τ was seen with increasing Yb3+ concentration, which confirms the increase in the population of trap centers. The positron annihilation lifetime (PAL) curve showed that 1mol% Yb3+ and 2mol Nd3+ have single vacancies or shallower positron traps, whereas 3mol% Yb3+ and 2mol% Nd3+ have larger defects like surface oxygen vacancy clusters. The other two samples have balance vacancies, which makes them best for thermometry applications. The fluorescence intensity ratio (FIR) was calculated to get sensitivity for thermometry application. 2.13% K-1 sensitivity achieved at 303-333K temperature.

Quenching-induced oxygen vacancy engineering boosts photocatalytic activities of CaTiO3

Oxygen vacancies (VOs) play a pivotal role in promoting the photocatalytic activities of perovskite oxides. Herein, we proposed a simple and effective strategy of introducing both surface oxygen vacancies and bulk single electron trapped oxygen vacancies (SETOVs) into CaTiO3 by ethanol quenching. The purchased CaTiO3 was preheated at 800 °C and then the hot CaTiO3 was quenched in ethanol instantly. The ethanol-quenched QE-CaTiO3 delivers much improved photocatalytic activities towards both RhB degradation and hydrogen evolution under visible light irradiation by 6.5 and 65.2 times, respectively, in comparison with the pristine CaTiO3. Both the bulk SETOVs and surface VOs enhance light absorption, and the surface VOs serve as photocatalytic active sites. DFT calculations further reveal the narrowed band gap and accumulated charge density near the Fermi level in QE-CaTiO3, which help the visible light absorption, facilitate charge carriers generation and migration, and promote photocatalytic activities. Our findings provide an efficient and easily scalable approach to engineering oxygen vacancy defects in photocatalysts and other catalysts.

The role of oxygen vacancies in enhancement of photocatalysis and ferromagnetism of (Mn, Co) co-doped ZnO nanoparticles

(Mn, Co) co-doped ZnO nanoparticles (NPs) were synthesized using the sol-gel method. Rietveld refined XRD patterns indicated that the NPs exhibited hexagonal wurtzite structures. Co and Mn ions were successfully introduced into the ZnO NPs at different concentrations. Moreover, Raman peak at 520 cm−1 was related to the defects induced by doping with Mn and Co ions. Fitting the O 1s XPS spectra of the NPs showed that more oxygen vacancies formed with increasing Co and Mn doping. Because there were more oxygen vacancies, photocatalytic dye degradation of rhodamine B enhanced at higher Co and Mn concentrations. Photoluminescence spectra showed that the NPs containing more Mn and Co had more single charged oxygen vacancies. The experimental and theoretical results showed that the exchange interactions between the Mn2+-Co2+ ions mediated by singly charged oxygen vacancies was responsible for room temperature ferromagnetism in the (Mn, Co) co-doped ZnO NPs.

First-principles study of lithium behavior in the ABA-stacking trilayer graphene with defects

To investigate the effect of defects on the Li embedding in graphene, we have studied the embedding and migration of Li in graphene with single-vacancy (SV), double-vacancy (DV), and Stone-Wales (SW) defects using the first-principles calculations. The results show that Li atom prefers to embed in regions with defect, and the presence of defect enhances the Li embedding in graphene. From the perspective of solution energy, Li embedded in the defect region of SV is the most stable, followed by the defect region of DV and SW. Migration results reveal that defects lead to an increase in the energy barrier for Li atom migration between layers and that Li is likely to be trapped in the defect region during migration. Open-circuit voltage and theoretical capacity calculations demonstrate that the lithium capacity of the ABA-stacking trilayer perfect graphene is 248 mAh/g. The lithium capacity diminishes to 165 mAh/g when a SW defect is present in the ABA-stacking trilayer graphene. In contrast, the lithium capacity increases to 270 mAh/g and 292 mAh/g when SV or DV defect is present in the ABA-stacking trilayer graphene, respectively. It is sufficient to show that graphene with low-density SW defect is unsuitable for application as electrode materials. Conversely, the low density of SV and DV defects can increase the lithium capacity of the ABA-stacking trilayer graphene at the same time, which will also lead to lithium deposition to some extent.

Mechanical properties of C3N-BN hybrid nanosheets: Insights from molecular dynamics simulations

Molecular dynamics simulations have been utilized to explore the mechanical properties of the C3N-BN hybrid nanosheet across varying temperatures and strain rates, as well as in the presence of two different types of defects: circular holes and single vacancy atoms introduced into the hybrid structure. The findings revealed that the hybrid material shows intermediate mechanical properties compared to pure C3N and BN. The mechanical characterization of the hybrid suggests that variations in mechanical parameters remain relatively stable across different strain rates. However, temperature changes significantly affect the mechanical properties of the hybrid, with the highest failure stress recorded as 123.70 (GPa), failure strain of 21.57 %, and Young's Modulus of 747.25 (GPa) at 100 Kelvin. Expanding the hole radius decreases failure stress by approximately 76 %, 56 %, and 82 % when holes are exerted in the interface, BN, and CN sides of the hybrid, respectively, and reduces Young's modulus by about 65 %, 67 %, and 66 %. Introducing circular holes within the BN domain enhanced the hybrid structure's strength and resilience, demonstrating BN's superiority over C3N. Therefore, placing holes in the BN region is recommended for achieving superior mechanical properties in such structures. The introduction of single-atom vacancies revealed that carbon vacancies induced a far more significant mechanical strength reduction than vacancies of other atoms.

Triangular graphene nanosheets, structures with extraordinary bending behavior.

Sometimes, manipulating the geometry or creating a defect can help the engineering of the nanostructured properties, such as increasing the frequency sensitivity of graphene nanosheets as a mass sensor by changing the geometry of the structure in a triangular shape and also by creating a vacancy or making nanodiodes in a triangular shape, which restricts the flow of heat in one direction and expands it in another direction. Then, the mechanical properties of the triangular geometry of graphene nanosheets have an excellent value for future devices. The results of the molecular dynamics study can illustrate the mechanical properties of graphene sheets well, which is particularly important. In this study, using molecular dynamics (MD) simulation, the bending stiffness of triangular graphene sheets was investigated to present a broader view of engineering applications of graphene sheets. Analyzing stress-displacement results of triangular graphene sheets in both zigzag and armchair directions under bending load reveals the effect of the directions of sheets on their bending stiffness. Also, comparing the bending stiffness of pristine and defective sheets showed that bending stiffness was decreased when an atom was removed from the middle of a sheet and made a single vacancy defected sheet. Obtained results suggest that triangular graphene nanosheets with higher bending stiffness, compared to rectangular sheets with the same number of atoms, are better for applications requiring higher bending properties, such as nanoelectromechanical devices. The reported results of this work provide an overall viewpoint concerning the geometry and defect effects on the graphene nanosheets' mechanical properties. The bending stiffness of triangular sheets was 20 and 10 times that of intrinsic and defective rectangular sheets, respectively.

Effect of vacancy defect on the structural and electrical properties of single-walled silicon nanotube

The effect of vacancy defects on zigzag and armchair single-walled silicon nanotubes (SiNTs) has been investigated using the self-consistent charge density functional tight-binding (SCC-DFTB) method. The findings indicate that the introduction of defects leads to the inability of the smaller-diameter tube to uphold its tubular structure and cluster. Conversely, the larger-diameter tube undergoes an elliptical transformation, yet retains tubular characteristics and hexagonal structures displaying specific symmetry. The double vacancy defect alters the atomic arrangement on the side opposite the defect. The stability of single-walled SiNTs is related to defect type and chiral index. In addition, the single vacancy defect increases the binding energy and stability of the zigzag tube, while causing a rapid decrease in stability of the armchair tube (7,7). The spin polarization phenomenon manifests within the defect tube, resulting in the splitting of the initial degenerate energy band and a significant decrease in its degeneracy. The existence of electronic interaction, results in a prominent manifestation of vacancy-induced magnetism in armchair and zigzag defect tubes. This phenomenon gives rise to localized spin-up bands situated below the Fermi level, as well as localized spin-down bands positioned above the Fermi level. In the energy band structure of most nanotubes, there are conduction bands or valence bands passing through the Fermi level, leading to a transition from semiconductor to semimetal or metal properties.

Vacancy-and doping-mediated electronic and magnetic properties of PtSSe monolayer towards optoelectronic and spintronic applications.

Developing new multifunctional two-dimensional (2D) materials with two or more functions has been one of the main tasks of materials scientists. In this work, defect engineering is explored to functionalize PtSSe monolayer with feature-rich electronic and magnetic properties. Pristine monolayer is a non-magnetic semiconductor 2D material with a band gap of 1.52(2.31) eV obtained from PBE(HSE06)-based calculations. Upon creating single Pt vacancy, the half-metallic property is induced in PtSSe monolayer with a total magnetic moment of 4.00 μ B. Herein, magnetism is originated mainly from S and Se atoms around the defect site. In contrast, single S and Se vacancies preserve the non-magnetic nature. However, the band gap suffers of considerable reduction of the order of 67.11% and 48.68%, respectively. The half-metallicity emerges also upon doping with alkali metals (Li and Na) with total magnetic moment of 1.00 μ B, while alkaline earth impurities (Be and Mg) make new diluted magnetic semiconductor materials from PtSSe monolayer with total magnetic moment of 2.00 μ B. In these cases, magnetic properties are produced mainly by Se atoms closest to the doping site. In addition, doping with P and As atoms at chalcogen sites is also investigated. Except for the half-metallic AsSe system (As doping at Se site), the diluted magnetic semiconductor behavior is obtained in the remaining cases. Spin density results indicate key role of the VA-group impurities in magnetizing PtSSe monolayer. In these cases, total magnetic moments between 0.99 and 1.00 μ B are obtained. Further Bader charge analysis implies the charge loser role of all impurities that transfer charge to the host monolayer. Results presented in this work may suggest promises of the defected and doped Janus PtSSe structures for optoelectronic and spintronic applications.

First principles study on the electronic structure and optical properties of Janus WSeTe with defects and strains

A Janus monolayer can be described as a two-dimensional material with distinct anions on either side of each layer. Two of these distinct chalcogen atoms are situated in the mirror-symmetric lattice positions of the transition metal atoms and are referred to as Janus transition metal dichalcogenides (TMDs). This material breaks the out-of-plane mirror symmetry and thus has excellent properties not found in conventional TMDs. However, during material synthesis, it can generate a number of defects that can substantially alter its properties. Therefore, in this article, the changes in the electronic structure and optical properties of Janus WSeTe when generating single vacancy defects, double vacancy defects and antisite defects have been investigated using first principles study. Assess the stability of the material through computations of its phonon spectrum, AIMD simulation and defect formation energy. Analyse its bandstructure, projected density of states, and optical absorption coefficient to present the change in its properties. The results show that the easiest and most stable form of defect is the substitution of Se atom for Te atom. These defect types change the bandgap value in different ways in Janus WSeTe, which further changes the peak optical absorption coefficient. The lattice constants undergo alterations during the defect generation process. For this purpose, we also investigated the changes in the properties of Janus WSeTe and its defects when subjected to biaxial tensile and compressive strains ranging from −9% to 9 %. As the tensile and compressive strains increase, a gradual decrease in the band gap value is observed. Our findings may serve as a theoretical basis for experiments in the synthesis of Janus WSeTe and the development of electronic devices using monolayer Janus WSeTe.

Possibility of defective monolayer graphene as potential anode material of metal-ion batteries

The necessitates exploration in the field of rechargeable metal ion batteries demands safe, cost-efficient, and face significant challenges in their development. Defect engineering may be helpful for the ion storage and diffusion in the battery anodes. In this paper, we use density functional theory to investigate the adsorption and diffusion behavior of Li, Mg, and Al atom on single vacancy (SV), Stone-Wales vacancy (SWV), double vacancy (DV) and quadruple vacancy (QV) defective monolayer graphene. It is evident that metal exhibits the strongest adsorption strengthen at the defect center. The DV and QV defective graphene shows the ideal diffusion energy barrier for three metals. Importantly, the QV structure exhibit maximum storage capacities of the 775 mAh/g for Li, 911 mAh/g for Mg, and 1543.4 mAh/g for Al respectively. Additionally, their open-circuit voltages are all in a very safe range. This study can support a strong basis for the experimental research for metal-ion battery anodes.

Mechanical Properties and Hydrogen Embrittlement Resistance of the High‐Entropy Alloy CrFeMnNiCo and Its Subsystems

The effects of hydrogen on the mechanical properties of CrNiCo and CrFeNiCo medium‐entropy alloys (MEAs) and CrFeMnNiCo high‐entropy alloys (HEAs) are investigated. Although their total elongation is less than that of the commonly used stainless steel (SS) 316L (SS316L), the tensile strengths of HEAs and MEAs are 150–350 MPa higher than that of SS316L. Hydrogen charging up to 1400 appm (nominal concentration) does not affect the tensile strength of SS316L; however, it decreases the elongation by less than 20%. In contrast, hydrogen increases the tensile strength of MEAs and HEA, but has little effect on elongation. Among the MEAs and HEAs, CrNiCo exhibits the highest tensile strength and total elongation. No brittle fracture due to hydrogen is observed on the fracture surfaces of the H‐charged samples. However, nanotwin structures are more common in H‐charged MEAs and HEAs than in H‐uncharged MEAs and HEA. Additionally, the calculation results based on the first‐principles reveal for the first time that single vacancies or tiny vacancy clusters do not trap H in MEAs compared to HEAs, such that cracks due to H are unlikely to occur. Thus, the hydrogen embrittlement resistance of MEAs may be improved.

Coupling field optimization to improve the thermal transport of Gr/h-BN heterostructure

We perform a numerical evaluation on the multi-physical field coupling effect to improve the interfacial thermal conductivity (ITC) of Gr/h-BN (Graphene/Hexagonal boron nitride) planar heterostructure. The model of Gr/h-BN planar heterostructure (C-BN bonded configuration) is built to investigate the effect of the multifactor coupling effect of different temperatures, N-doping concentration, and single vacancy concentration on the ITC. Finally, the Box-Behnken orthogonal model is established to determine the optimal value of ITC under the coupling effect of multi-physical fields by response surface analysis, and the optimal value of ITC is 14.456 GW m−2 K−1 when the temperature is 673 K, the single vacancy is 2.57 %, and the N-doping is 18.9 %. It implies that the proper coupling configuration is found effective in improving the interfacial thermal conductivity of the Gr/h-BN heterostructure. This work is hoped to help promote the thermal reliability design of graphene heterogeneous interface for related micro/nano semiconductor devices.

First-principles study of Ni clusters growth on graphene with a vacancy

In this work, we performed first-principles calculations to study the interactions of Nin clusters (n = 2-5) with graphene. Nin clusters were adsorbed on pristine graphene and graphene with a vacancy. We observed that the adsorption energy is significantly lowered when graphene has a single vacancy. The single vacancy gives place to a charge redistribution that favors chemisorption. The dangling bonds of the carbon atoms produced by the vacancy increase the magnetic moment of the C atoms around the hole induced by the Ni clusters. We found that the situation is very different when the Ni cluster is adsorbed with atoms on both sides of the vacancy. We consider the cases in which one of the Ni atoms is located on one side of the graphene sheet and the rest on the other, Nin,1. The adsorption energy for Ni3,1 and Ni4,1 clusters are slightly larger than when the whole cluster is chemisorbed on one side only, but the charge redistribution, occurring on both sides of the graphene, increases the possibility to adsorb other molecules. For all cases, we analyzed the electronic density of states to account for the electronic changes on the graphene sheet as a function of the size of the Nin cluster. Finally, the Bader effective charges were computed to follow the charge transfer between Nin clusters and the graphene atoms.

INVESTIGATION OF THERMAL CONDUCTIVITY IN SINGLE-WALLED (n,n) CARBON NANOTUBES USING MOLECULAR DYNAMICS SIMULATION

Single-walled carbon nanotubes (SWCNTs) are captivating materials renowned for their outstanding thermal properties and diverse applications in nanotechnology. This study utilizes molecular dynamics simulations to investigate the factors influencing thermal conductivity in SWCNTs, namely diameter, length, temperature, and defects. Results reveal that thermal conductivity exhibits an increase with both diameter and length, with values ranging from 3100 to 3400 W/m·K for diameters varying from 0.68 to 1.70 nm , and from 2800 to 3700 W/m·K for lengths ranging from 20 to 200 nm . Conversely, thermal conductivity demonstrates a decrease with rising temperatures, with values dropping from 3400 to 2600 W/m·K as temperature increases from 100 to 700 K . Furthermore, the presence of defects significantly diminishes thermal conductivity, as illustrated by reductions from 3200 to 2900 W/m·K for single vacancy defects and further to 2500 W/m·K for double vacancies. These findings insights into the thermal behavior of SWCNTs, enhancing our understanding of their thermal properties and broadening their potential applications, including in nanoscale cooling and nanoelectronics

The Defects Genome of Janus Transition Metal Dichalcogenides.

2D Janus Transition Metal Dichalcogenides (TMDs) have attracted much interest due to their exciting quantum properties arising from their unique two-faced structure, broken-mirror symmetry, and consequent colossal polarization field within the monolayer. While efforts are made to achieve high-quality Janus monolayers, the existing methods rely on highly energetic processes that introduce unwanted grain-boundary and point defects with still unexplored effects on the material's structural and excitonic properties Through high-resolution scanning transmission electron microscopy (HRSTEM), density functional theory (DFT), and optical spectroscopy measurements; this work introduces the most encountered and energetically stable point defects. It establishes their impact on the material's optical properties. HRSTEM studies show that the most energetically stable point defects are single (VS and VSe) and double chalcogen vacancy (VS -VSe), interstitial defects (Mi), and metal impurities (MW) and establish their structural characteristics. DFT further establishes their formation energies and related localized bands within the forbidden band. Cryogenic excitonic studies on h-BN-encapsulated Janus monolayers offer a clear correlation between these structural defects and observed emission features, which closely align with the results of the theory. The overall results introduce the defect genome of Janus TMDs as an essential guideline for assessing their structural quality and device properties.

Searching for new two-dimensional spintronic materials: Doping-induced magnetism in graphene-like SrS monolayer

In this work, doping approach is explored to induce feature-rich electronic and magnetic properties in graphene-like SrS monolayer and make it prospective spintronic two-dimensional (2D) candidate. For such goal, 3d transition metals (V, Cr, Mn, and Fe) and halogens (F, Cl, Br, and I) are selected as dopants at Sr and S sublattice, respectively. Pristine SrS single layer shows good dynamical and thermal stability. Its indirect-gap semiconductor nature is also asserted with energy gap of 2.87/3.81 eV obtained by PBE/HSE06 functional, generated by the separation in energy between S-3p and Sr-4d orbitals. The magnetic semiconducting with total magnetic moment of 2.00 μB is obtained by creating a single Sr vacancy, meanwhile S single vacancy preserves the non-magnetic nature. The monolayer is significantly magnetized by doping with transition metals, where large total magnetic moments of 3.00, 4.00, and 5.00 μB are obtained for the V-, Cr/Fe-, and Mn-doped SrS monolayer, respectively. In these cases, impurities play a key role on producing magnetic properties and generating the magnetic semiconductor nature. This feature-rich nature is also induced by doping with F atom, where a total magnetic moment of 1.00 μB is obtained that is originated mainly from Sr atoms closest to the doping site. Besides, Cl doping leads to the emergence of the half-metallicity. Importantly, the magnetization becomes significantly weaker according to increase the atomic number of halogen dopants, such that the non-magnetic nature is preserved by doping with I atom. This feature is attributed to the increase of the electronic hybridization. Results presented herein introduce the doped SrS monolayer as promising 2D spintronic materials, exhibiting novel properties that are not found in the pristine counterpart.

Chemical bonding and electronic properties along Group 13 metal oxides

ContextThe present work provides a systematic theoretical analysis of the nature of the chemical bond in Al2O3, Ga2O3, and In2O3 group 13 cubic crystal structure metal oxides. The influence of the functional in the resulting band gap is assessed. The topological analysis of the electron density provides unambiguous information about the degree of ionicity along the group which is linearly correlated with the band gap values and with the cost of forming a single oxygen vacancy. Overall, this study offers a comprehensive insight into the electronic structure of metal oxides and their interrelations. This will help researchers to harness information effectively, boosting the development of novel metal oxide catalysts or innovative methodologies for their preparation.MethodsPeriodic density functional theory was used to predict the atomic structure of the materials of interest. Structure optimization was carried out using the PBE functional, using a plane wave basis set and the PAW representation of the atomic cores, using the VASP code. Next, the electronic properties were computed by carrying out single point calculations employing PBE, PBE + U functionals using VASP and also with PBE and the hybrid HSE06 functionals using the FHI-AIMS software. For the hybrid HSE06, the impact of the screening parameter, ω, and mixing parameter, α, on the calculated band gap has also been assessed.