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This research is being conducted to learn more about various compounds and their potential uses in various fields such as renewable energy, electrical conductivity, the study of optoelectronic properties, the use of light-absorbing materials in photovoltaic device thin-film LEDs, and field effect transistors (FETs). AgZF3 (Z = Sb, Bi) compounds, which are simple, cubic, ternary fluoro-perovskites, are studied using the FP-LAPW and low orbital algorithm, both of which are based on DFT. Structure, elasticity and electrical and optical properties are only some of the many features that can be predicted. The TB-mBJ method is used to analyze several property types. An important finding of this study is an increase in the bulk modulus value after switching Sb to Bi as the metallic cation designated as "Z" demonstrates the stiffness characteristic of a material. The anisotropy and mechanical balance of the underexplored compounds are also revealed. Our compounds are ductile, as evidenced by the calculated Poisson ratio, Cauchy pressure, and Pugh ratio values. Both compounds exhibit indirect band gaps (X-M), with the lowest points of the conduction bands located at the evenness point X and the highest points of the valence bands located at the symmetry point M. The principal peaks in the optical spectrum can be understood in light of the observed electronic structure.
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Algoritmos , Compuestos de Calcio , Anisotropía , ElectrónicaRESUMEN
This work describes an ab initio principle computational examination of the optical, structural, elastic, electronic and mechanical characteristics of aluminum-based compounds AlRF3 (R = N, P) halide-perovskites. For optimization purposes, we used the Birch-Murnaghan equation of state and discovered that the compounds AlNF3 and AlPF3 are both structurally stable. The IRelast software was used to compute elastic constants (ECs) of the elastic properties. The aforementioned compounds are stable mechanically. They exhibit strong resistance to plastic strain, possess ductile nature and anisotropic behavior and are scratch-resistant. The modified Becke-Johnson (Tb-mBJ) approximation was adopted to compute various physical properties, revealing that AlNF3 and AlPF3 are both metals in nature. From the density of states, the support of various electronic states in the band structures are explained. Other various optical characteristics have been calculated from the investigations of the band gap energy of the aforementioned compounds. These compounds absorb a significant amount of energy at high levels. At low energy levels, the compound AlNF3 is transparent to incoming photons, whereas the compound AlPF3 is somewhat opaque. The examination of the visual details led us to the deduction that the compounds AlNF3 and AlPF3 may be used in making ultraviolet devices based on high frequency. This computational effort is being made for the first time in order to investigate the aforementioned properties of these chemicals, which have yet to be confirmed experimentally.
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Tin-based nanocomposite materials embedded in carbon frameworks can be used as effective negative electrode materials for lithium-ion batteries (LIBs), owing to their high theoretical capacities with stable cycle performance. In this work, a low-cost and productive facile hydrothermal method was employed for the preparation of a Sn/C nanocomposite, in which Sn particles (sized in nanometers) were uniformly dispersed in the conductive carbon matrix. The as-prepared Sn/C nanocomposite displayed a considerable reversible capacity of 877 mAhg-1 at 0.1 Ag-1 with a high first cycle charge/discharge coulombic efficiency of about 77%, and showed 668 mAh/g even at a relatively high current density of 0.5 Ag-1 after 100 cycles. Furthermore, excellent rate capability performance was achieved for 806, 697, 630, 516, and 354 mAhg-1 at current densities 0.1, 0.25, 0.5, 0.75, and 1 Ag-1, respectively. This outstanding and significantly improved electrochemical performance is attributed to the good distribution of Sn nanoparticles in the carbon framework, which helped to produce Sn/C nanocomposite next-generation negative electrodes for lithium-ion storage.
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This paper explains our first-principle computational investigation regarding the structural, optical, elastic, and electrical characteristics of gallium-based GaMF3 (M = Be and Ge) perovskite-type (halide-perovskite) compounds. Our current computation is based on density functional theory (DFT) and is achieved with the help of the WIEN2k code. We used the Birch-Murnaghan equation for optimization; in both compounds, we found that both GaBeF3 and GaGeF3 compounds are structurally stable. For the computation of elastic characteristics, the IRelast package for calculating elastic constants (ECs) is utilized. These compounds are mechanically ductile, scratch-resistant, anisotropic, and mechanically stable, showing huge opposition to plastic strain. The modified Becke-Johnson (TB-mBJ) potential approximation method is used to calculate different physical characteristics and shows that GaGeF3 behaves as a metal, whereas the GaBeF3 compound is insulating in nature. The involvement of various electronic states in band structures is calculated using the theory of the density of states. The different optical properties of these compounds can be studied easily using their band gap energy. At high energy ranges, these substances demonstrate strong absorption. At low energies, the GaGeF3 compound is transparent, while the GaBeF3 compound is opaque to incoming photons. Investigation of the optical characteristics has led us to the conclusion that both GaGeF3 and GaBeF3 compounds can be used for high-frequency ultraviolet device applications. This computational work is considered to be the first time that we can study these compounds, which to our knowledge have not previously been experimentally validated.
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Sulfuryl fluoride (SO2F2) is one of the ideal decomposition components of sulfur hexafluoride (SF6), which is widely used as an insulating and arc extinguishing medium in gas-insulated switchgear. To detect the decomposition component of SF6at room temperature, the use of SO2F2is still a challenge. In this work, we have successfully fabricated TiO2nanofibers and nickel sulfate (NiSO4NPs) via simple electrospun and hydrothermal methods, followed by calcination process to improve the sensing performance. Metal oxide semiconductor materials (MOSs) are widely used in gas sensing applications due to their superior performance and fast recovery speed. Although the performance of our TiO2/NiSO4composite nanofiber sensor decreases at higher temperatures, it shows an excellent response to target gasses at room temperature. Ni-decoration on the outer surface of the nanofibers could maximize the sensing response of 100 ppm SO2F2by up to 189% at room temperature, showing that the TiO2/NiSO4composite nanofibers are 2.5 times superior to the pure TiO2nanofiber sensors. Thus, the approach for this novel composite nanofiber-based material is promising for the fabrication of superior gas sensors for decomposition of SF6.
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A middle aged male underwent series of percutaneous coronary intervention (PCI) of left main stenosis for Canadian cardiovascular society (CCS) IV angina. He developed recurrent severe proliferative in-stent restenosis which was treated with different available options including drug-eluting stents and finally with drug-eluting balloons. During his treatment, challenges of PCI including left main chronic total occlusion PCI, complications like coronary perforation were encountered and treated successfully.
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Angioplastia Coronaria con Balón/instrumentación , Puente de Arteria Coronaria/métodos , Estenosis Coronaria/cirugía , Stents Liberadores de Fármacos , Anciano , Angiografía Coronaria , Reestenosis Coronaria/diagnóstico por imagen , Reestenosis Coronaria/cirugía , Estenosis Coronaria/diagnóstico por imagen , Estudios de Seguimiento , Humanos , Masculino , Diseño de Prótesis , ReoperaciónRESUMEN
The optoelectronic, structural, and elastic properties of K2ScCuCl6 and K2YCuCl6 double perovskite compounds were thoroughly investigated in this study using density functional theory. It is observed that both compounds exhibit exceptional structural and mechanical stability. The structural stability is assessed using Goldsmith's tolerance factor (tG), with values approaching unity indicating a reliable cubic perovskite structure. Phonon stability was ensured by the absence of negative energy formations and only real frequencies in the phonon calculations. Applying the finite displacement method also provided further evidence of the compounds' thermodynamic stability. The electronic properties analysis revealed that K2ScCuCl6 and K2YCuCl6 are narrow band gap semiconductors, with band gap values of 1.8 and 2.5 eV, respectively. This was confirmed by analyzing the density of states. Furthermore, the optical properties exhibited transparency at lower photon energies and significant absorption at higher energies. These exciting findings suggest that K2ScCuCl6 and K2YCuCl6 have promising applications in high-frequency UV devices.
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Neuromorphic computing is a new field of information technology, which is inspired by the biomimetic properties of the memristor as an electronic synapse and neuron. If there are electronic receptors that can transmit exterior impulses to the internal nervous system, then the use of memristors can be expanded to artificial nerves. In this study, a layer type memristor is used to build an artificial nociceptor in a very feasible and straightforward manner. An artificial nociceptor is demonstrated here through the fabrication and characterization of a cobalt-doped zinc oxide (CZO)/Au based memristor. In order to increase threshold switching performance, the surface effects of the CZO layer are eliminated by adding cobalt cobalt-doped zinc oxide (CZO) layer between the P++-Si and Au electrodes. Allodynia, hyperalgesia, threshold, and relaxation are the four distinct nociceptive behaviours that the device displays based on the strength, rate of relapse, and duration of the external stimuli. The electrons that are trapped in or released from the CZO layer's traps are responsible for these nociceptive behaviours. A multipurpose nociceptor performance is produced by this type of CZO-based device, which is crucial for artificial intelligence system applications such as neural integrated devices with nanometer-sized characteristics.
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The objective of this research was to produce the smallest possible ZnO nanoparticles through an adapted wet chemical process and subsequently, to fabricate a core-shell structure utilizing polyethylene glycol (PEG) as the shell component. The synthesis, size, and shape of the NPs were confirmed using advanced techniques. The resulting clustered NPs were round and had a size of 9.8 nm. Both plain and core-shell NPs were tested for their antibacterial properties against multi-drug resistant bacteria strains (E. cloacae, E. amnigenus, S. flexneri, S. odorifacae, Citrobacter, and E. coli), with concentrations of 500, 1000, and 1500 µg ml-1 used for testing. Both types of NPs demonstrated antibacterial activity against the tested pathogens, with the core-shell NPs being more effective. The synthesized NPs were biocompatible with human red blood cells, with a low level of hemolysis observed. The biocompatibility of the core-shell NPs was significantly enhanced by the presence of the PEG added as the shell. In addition, their effectiveness as photosensitizers for cancer treatment via photodynamic therapy (PDT) was evaluated. MTT assay was used to evaluate the cytotoxicity of ZnO and PEG-ZnO, and the results showed that these NPs were able to generate ROS inside tumor cells upon irradiation, leading to apoptosis and cell death, making them a promising candidate for PDT.
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One possible result of low-level characteristics in the traditional von Neumann formulation system is brain-inspired photonics technology based on human brain idea. Optoelectronic neural devices, which are accustomed to imitating the sensory role of biological synapses by adjusting connection measures, can be used to fabricate highly reliable neurologically calculating devices. In this case, nanosized materials and device designs are attracting attention since they provide numerous potential benefits in terms of limited cool contact, rapid transfer fluidity, and the capture of photocarriers. In addition, the combination of classic nanosized photodetectors with recently generated digital synapses offers promising results in a variety of practical applications, such as data processing and computation. Herein, we present the progress in constructing improved optoelectronic synaptic devices that rely on nanomaterials, for example, 0-dimensional (quantum dots), 1-dimensional, and 2-dimensional composites, besides the continuously developing mixed heterostructures. Furthermore, the challenges and potential prospects linked with this field of study are discussed in this paper.
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Using the density functional theory (DFT) method, we investigate the properties of LaXSi (X = Pt, Pd) half-Heusler compounds. To ensure the stability of both compounds, we employed two criteria: the Birch-Murnaghan equation of state and the negative formation energy. The evaluation of elastic constants (ECs) plays a crucial role in determining the mechanical stability of both compounds. Specifically, we ensure that the conditions C11 - C12 > 0, C11 > 0, C11 + 2C12 > 0, and B > 0 are satisfied and exhibit mechanical anisotropy and ductility. The analysis of electronic properties clearly indicates that LaPtSi displays metallic behavior in both the spin-up and spin-down states. In the spin-up state of LaPdSi, a band gap is observed, which indicates its characteristic of being a half-metal. A comprehensive investigation of optical properties revealed that these compounds display notable absorption and optical conductivity at higher energy levels. Conversely, they exhibit transparency to incident photons at lower energy levels. Based on the findings, it can be concluded that these compounds are highly suitable for application in high-frequency UV devices. The thermoelectric properties clearly indicate that both materials exhibit high power factors, electrical conductivity, and figures of merit (ZT), suggesting their potential as exceptional thermoelectric materials. The simulations conducted in this study consider the effect of on-site Coulomb interactions by incorporating the Hubbard U term within the GGA + U. Our findings contribute valuable insights that can facilitate further experimental investigations and provide comprehensive validation.
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We use WIEN2K to conduct density functional theory computations to explore the structural, thermodynamic, optoelectronic, and mechanical properties of fluoroperovskites QMnF3 (Q = Ga, In). The application of the Birch-Murnaghan equation to the energy versus volume, formation energy, and tolerance factor confirms the structural stability of these two QMnF3 (Q = Ga, In) materials. The thermodynamic stability of the compounds is confirmed by the results of the phonon calculation, while the mechanical stability is confirmed from the values of the elastic constants. GaMnF3 demonstrates a high capacity to withstand both compressive and shear stresses. A lower bulk modulus is responsible for the weaker ability of InMnF3 to endure changes in volume. Compared to GaMnF3, InMnF3 possesses rigidity having greater shear modulus, indicating greater resistance to changes in shape. However, both compounds are characterized as mechanically brittle, anisotropic, and ductile. The band structure that was determined indicates that both GaMnF3 and InMnF3 exhibit a metallic character. The density of states analysis further supports the metallic nature of GaMnF3 and InMnF3. In GaMnF3, the "Mn" and "F" atoms in the valence band significantly participate in the total density of states, whereas in InMnF3, both "Mn" and "F" atoms also dominate the total density of states. The values of ε1(0) computed for GaMnF3 and InMnF3 are positive i.e. > 0, and agree with Penn's model. We calculate the optical properties for both GaMnF3 and InMnF3 and the potential of these materials of interest for applications in optoelectronic gadgets including light-emitting diodes is attributed to their absorption in the ultraviolet-visible zone. We believe that this work may provide comprehensive insight, encouraging further exploration of experimental studies.
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In our pursuit of enhancing material performance, our focus is centered on the investigation of sodium-based halide perovskites, specifically NaXCl3 (where X = Be & Mg). We are utilizing first-principles methods based on density functional theory (DFT) to delve into these materials' properties and potential improvements. This investigation is executed using the WIEN2K code, aiming to uncover a deeper understanding of these materials' properties and potential enhancements. In this study, we utilize the Full Potential Linear Augmented Plane Wave (FP-LAPW) approach to analyze the structural, mechanical, electronic, and optical properties of cubic perovskite materials NaXCl3 (X = Be, Mg). We employ the Birch-Murnaghan fitting curve to assess the structural stability of these compounds, and in each case, the compound demonstrates structural stability in its optimal or ground state. The existence of real frequencies serves as confirmation of the phonon stability for both compounds. To determine the elastic characteristics, the IRelast Package is used. This involves calculating the elastic constants, which demonstrates that the compounds have anisotropic, ductile properties and demonstrate mechanical stability. We investigate the electronic properties by analyzing the density of states and the band structure. Both compounds exhibit an indirect band gap energy of 4.15 eV for NaBeCl3 and 4.16 eV for NaMgCl3. We analyze both the total and partial density of states to gain insight into the contributions of different electronic states to the band structure. Furthermore, optical characteristics, including the dielectric function, absorption coefficient, refractive index, and reflectivity, are investigated across an energy spectrum ranging from 0 to 15 eV. These findings can offer a comprehensive insight into the development of advanced electronic devices with improved efficiency and enhanced capabilities. Furthermore, they have the capacity to inspire experimental researchers to delve further into this field for subsequent explorations.
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Coded within Wien2K, we carry out DFT-based calculations for investigations of the structural, elastic, optoelectronic, and thermoelectric properties of BaXF3 (X = Co, Ir) fluoro-perovskites. The Birch-Murnaghan fit to the energy-vs-volume data and formation energy shows that these fluoro-perovskites are structurally stable. The phonon calculation confirms the thermodynamic stability, while the relation between elastic constants such as C 11 - C 12 > 0, C 11 > 0, C 11 + 2C 12 > 0, and B > 0 validates the mechanical stability of the compounds. BaIrF3 exhibits a strong ability to endure compressive and shear stresses. BaCoF3 shows a weaker capacity of withstanding changes in volume, attributed to a lower bulk modulus. Demonstrating a higher G-modulus of rigidity than the BaIrF3, BaCoF3 demonstrates stronger resistance to change the shape and both compounds are found to be anisotropic and brittle. The determined band structure profiles reveal that both BaCoF3 and BaIrF3 demonstrate a metallic nature. In addition, the metallic nature of BaCoF3 and BaIrF3 is reinforced by the density-of-states (DOS) study, where Co and F atoms contribute significantly to the total DOS in the valence band in the case of BaCoF3, while that of BaIrF3 is predominated by the Ba and F atoms. The computed values of ε1(0) for BaCoF3 and BaIrF3 are approximately 30 and 19, respectively, which are in line with Penn's model. The researched materials are confirmed to be strong contenders for optoelectronics by the lack of absorption in the visible range. For their potential use in thermoelectric device applications, thermoelectric parameters such as temperature-dependent Seebeck coefficient, specific heat capacity, thermal conductivity, power factor, and figure of merit are also investigated, which show that these materials are thermally stable and promising for applications in thermoelectric devices.
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Orthorhombic oxide perovskite compounds are very promising materials for the applications of optoelectronics and thermal barrier coating. This work represents a numerical simulation of YBO3 compounds through the first-principles ab initio approach. The electronic and magnetic properties are investigated employing the general gradient approximation (GGA) coupled to the integration of the Hubbard U-term which is the GGA + U. The Ti and Fe-based YBO3 perovskite compounds are found to be actively promising within the ferromagnetic configuration and their lattice parameters are consistent with the previous studies. The calculations of formation energy signify that the compounds YBO3 are stable thermodynamically. The electronic properties are computed and evaluated by the band structure and density of states for both compounds and the results depict that these materials are ferromagnetic half-metallic. Mechanically these compounds are stable, ductile, anisotropic, and hard to scratch. The thermal properties are evaluated for YBO3 (B = Ti and Fe) compounds up to a temperature range of 2000 K. This work can open new opportunities for further exploration in this field.
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Nanomaterials and nanoparticles are a burgeoning field of research and a rapidly expanding technology sector in a wide variety of application domains. Nanomaterials have made exponential progress due to their numerous uses in a variety of fields, particularly the advancement of engineering technology. Nanoparticles are divided into various groups based on the size, shape, and structural morphology of their bodies. The 21st century's defining feature of nanoparticles is their application in the design and production of semiconductor devices made of metals, metal oxides, carbon allotropes, and chalcogenides. For the researchers, these materials then opened a new door to a variety of applications, including energy storage, catalysis, and biosensors, as well as devices for conversion and medicinal uses. For chemical and thermal applications, ZnO is one of the most stable n-type semiconducting materials available. It is utilised in a wide range of products, from luminous materials to batteries, supercapacitors, solar cells to biomedical photocatalysis sensors, and it may be found in a number of forms, including pellets, nanoparticles, bulk crystals, and thin films. The distinctive physiochemical characteristics of semiconducting metal oxides are particularly responsible for this. ZnO nanostructures differ depending on the synthesis conditions, growth method, growth process, and substrate type. A number of distinct growth strategies for ZnO nanostructures, including chemical, physical, and biological methods, have been recorded. These nanostructures may be synthesized very simply at very low temperatures. This review focuses on and summarizes recent achievements in fabricating semiconductor devices based on nanostructured materials as 2D materials as well as rapidly developing hybrid structures. Apart from this, challenges and promising prospects in this research field are also discussed.
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To enhance the effectiveness of materials, we are motivated to investigate lithium-based halide perovskites LiRCl3 (where R = Be and Mg) using first-principles techniques based on density functional theory (DFT), implemented in the WIEN2K code. In this study, the research makes use of the WIEN2K simulation code, employing the plane-wave and self-consistent (PWSCF) approach. The cut-off energy, responsible for distinguishing core and valence states, is established at -6.0 Ry. To guarantee well-converged solutions with 2000 K points, parameters of RMT × Kmax = 7.0 are selected, where RMT represents the smallest muffin-tin radius and Kmax denotes the plane wave cut-off. Convergence is determined to be attained when the overall energy of the system remains unchanged during self-consistent calculations, reaching a threshold of 0.001 Ry. We observe structural stability of these materials using the Birch-Murnaghan fit, tolerance factor and formation energy. The tolerance factor for LiMgCl3 and LiBeCl3 are 1.03 and 0.857, while the formation energy for LiMgCl3 and LiBeCl3 are -7.39 eV and -8.92 eV respectively, confirming these to be stable structurally. We evaluate the electronic properties of the current materials, shedding light on their nature, by using the suggested modified Becke-Johnson potential. It turns out that they are indirect insulators, with calculated band gaps of 4.02 and 4.07 eV for LiMgCl3 and LiBeCl3, respectively. For both materials, we also calculate the density of states (DOS), and our findings regarding the band gap energies are consistent with the band structure. It is observed that both materials exhibit transparency to low-energy photons, with absorption and optical conduction occurring in the UV range. These compounds are mechanically stable, according to the elastic investigation, however LiBeCl3 shows higher resistance to compressive and shear loads as well as resistance to shape change. On the other hand, LiMgCl3 exhibits weaker resistance to changes in volume. Furthermore, we discovered that none of the compounds are entirely isotropic, and specifically, LiMgCl3 and LiBeCl3 are brittle in nature. These materials appear to be potential candidates for use in optoelectronic devices based on our analysis of their optical properties. Our findings may provide comprehensive insight, invoking experimental studies for further investigations.
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[This corrects the article DOI: 10.1039/D3RA02640J.].
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We investigated the physical behavior of SrMO3 (M = Hf and Pt) compounds, which are strontium-based oxide perovskites. We utilized the WIEN2k software to simulate and investigate their physical properties. The structural stability of SrHfO3 and SrPtO3 was verified using the Birch-Murnaghan equation of states for optimization. We also checked the elastic stability through the computation of elastic constants using the IRelast software. Our results indicate the stability of these compounds and showed their anisotropic, ductility, scratch-resistive, and plastic strain-resistant characteristics. Using the TB-mBJ potential approach, we determined that SrHfO3 is an insulator, whereas SrPtO3 is a metal in nature. The density of states computations was used to find the band structure as well as the contribution of different electronic states. Optical property research was conducted using the band gap energies of these substances. Our findings suggest that these crystals have low energy absorption and reflectivity of up to 65%, making them suitable for use in high-frequency UV devices. Specifically, SrHfO3 is more transparent before the energy point 2.80 eV, while the compound SrPtO3 after 6.50 eV to 12.0 eV and SrHfO3 from 12.0 and 14.0 eV. This study represents the first DFT-based investigation of these discussed crystals according to the best of our knowledge.
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Herein, the optoelectronic, structural, thermoelectric, and elastic characteristics of M2LiCeF6 (M = Rb and Cs) double perovskite compounds were investigated using ab initio modeling in the DFT framework. The Birch-Murnaghan fitting curve used for the optimization showed that these two compounds are structurally stable. The elastic properties of the M2LiCeF6 (M = Rb and Cs) double perovskite compounds were examined using the IRelast code. The results showed that these two compounds possess mechanical stability, anisotropy, and toughness, and offer resistance to plastic deformation. The precise and accurate determination of their electronic properties was achieved via the Trans-Blaha-modified Becke-Johnson (TB-mBJ) approximation. The Rb2LiCeF6 and Cs2LiCeF6 compounds are narrow band gap semiconductors with band gaps of 0.6 eV and 0.8 eV at the high symmetrical points from (Γ-M), respectively, exhibiting an indirect nature. To further understand how the various states contribute to the different band structures, total and partial density of state (DOS) computations were performed. The optical properties in the energy range of 0-40 eV for Rb2LiCeF6 and Cs2LiCeF6 were explored. The selected materials show transparency in the low incident photon energy range and have large light absorption and transmission at higher photon energies. Thus, it can be concluded that Rb2LiCeF6 and Cs2LiCeF6 can be used in high-frequency UV devices based on their optical characteristics. Both materials exhibit high electrical conductivity, power factors, and figures of merit (ZT) and act as effective thermoelectric resources. To the best of our knowledge, this is the first theoretical research on the optoelectronic, structural, thermoelectric, and elastic features of M2LiCeF6 (M = Rb and Cs).