Values Of Lattice Constants Research Articles

Technology of fabrication of CdSxTe1-x solid solution on silicon substrate

Heterojunction between Si and CdSxTe1-x have been obtained by the method of vacuum deposition of powders of cadmium sulfide and cadmium telluride on the surface of monocrystalline silicon. The optimal temperature regime for the growth of the CdSxTe1-x solid solution on the silicon surface has been determined. The values of the crystal lattice constant and the thickness of the CdSxTe1-x solid solution at the interface of the n/Si – n/CdSxTe1-x heterostructure are calculated.

Structural, Morphology, Electrical Polarization and FTIR Properties of Zn Substituted T-type Hexagonal Ferrites

A series of divalent Zn substituted T-type hexagonal ferrite material having the composition (x= 0.0, 0.02, 0.06, 0.1) was synthesized by using the sol-gel auto combustion method. Structural, morphological, optical, and electrical properties of T-type hexagonal ferrite were explored by using an X-ray diffractometer, scanning electron microscopy, Fourier transform infrared spectroscopy and Precision multiferroic II. The X-ray diffraction (XRD) patterns showed the single hexagonal phase ferrites for all the samples. With the substitution of the ions, the change in the values of lattice constants ‘a’, ‘c’ and unit cell volume was observed. The Debye Scherrer formula was used to calculate the crystallite size which was determined to be varied in the range of 26.3nm to 28.3nm. FTIR spectra also indicated that the present synthesized material had single-phase hexagonal structure. SEM micrographs revealed the agglomeration of small grains. The average grain size was found to be 0.331um which might be suitable for microwave absorption applications. The Polarization verse Electric field (P-E) loops unveiled the increase in saturation and remnant polarization. The P-E loops also exhibited the lossy behavior after substitution and the increase in lossy behavior with substitution results in an increase in conductivity of the material.

Modeling the structural, electronic, optoelectronic, thermodynamic, and core-level spectroscopy of X–SnO3 (X=Ag, Cs, Hf) perovskites

Tin-based cubic perovskites have gained increasing scientific interest as an alternative to lead-based perovskite materials in industrial applications of photovoltaic and optoelectronic devices due to their lesser toxicity, affordability, and availability. Thus, using the density functional theory (DFT) approach, the structural, electronic, optoelectronic, thermodynamic, phonon, and X-ray spectroscopic properties of XSnO3 (X = Ag, Cs, Hf) perovskite materials were investigated. For structural, electronic, and optoelectronic property computations, the Quantum Espresso Simulation Package (QESP) with the PBE-GGA functional was used, whereas phonon dispersion, phonon density of states, thermodynamics, and X-ray spectroscopy were computed using the Cambridge Serial Total Energy Package (CASTEP) code. Our calculations revealed that the calculated lattice constant values of XSnO3 (X = Ag, Cs, Hf) increased as the size of the cation X (X = Ag, Cs, Hf) increased. The valence bands were dominated by sn-4d orbital contributions for partial density of states. O-2p electrons, on the other hand, are crucial in the formation of conduction bands. Per the band structure, CsSnO3 has a metallic property with no band gap, HfSnO3 is a semiconductor with a band gap of 3.90 eV, and AgSnO3 is an insulator with a band gap of 4.30 eV. In addition, the dielectric function, extinction coefficient, and refractive index calculations were performed in the energy range of 0–10 eV. Furthermore, for each perovskite studied, we calculated thermodynamic parameters as a function of temperature. We discovered an exponential increase in entropy and a nearly linear pattern of enthalpy increase with temperature. These results show that the XSnO3 (X = Ag, Cs, Hf) materials absorb UV light and may be used to absorb UV rays. But relative to AgSnO3 and HfSnO3 materials, CsSnO3 is a better choice for usage in optoelectronic applications.

Discovery of High-Entropy Oxide Electrocatalysts: From Thin-Film Material Libraries to Particles.

Discovery of new high-entropy electrocatalysts requires testing of hundreds to thousands of possible compositions, which can be addressed most efficiently by high-throughput experimentation on thin-film material libraries. Since the conditions for high-throughput measurements ("screening") differ from more standardized methods, it is frequently a concern whether the findings from screening can be transferred to the commonly used particulate catalysts. We demonstrate the successful transfer of results from thin-film material libraries to particles of Cantor alloy oxide (Co-Cr-Fe-Mn-Ni)3O4. The chemical compositions of the libraries, all single-phase spinels, cover a wide compositional range of (Cr8.1-28.0Mn11.6-28.4Fe10.6-39.0Co11.4-36.7Ni13.5-31.4)37.7±0.6O62.3±0.6, with composition-dependent lattice constant values ranging from 0.826 to 0.851 nm. Electrochemical screening of the libraries for the oxygen evolution reaction (OER) identifies (Cr24.6±1.4Mn15.7±2.0Fe16.9±1.8Co26.1±1.9Ni16.6±1.7)37.8±0.8O62.2±1.2 as the most active composition, exhibiting an overpotential of 0.36 V at a current density of 1 mA cm-2. This "hit" in the library was subsequently synthesized in the form of particles with the same composition and crystal structure using an aerosol-based synthesis strategy. The similar OER activity of the most active thin-film composition and the derived catalyst particles validates the proposed approach of accelerated discovery of novel catalysts by screening of thin-film libraries.

Study of the suitability of manganese-substituted cobalt ferrites nanoparticles as MRI contrast agent and treatment by employing hyperthermia temperature

Ferrite-based nanoparticles have initiated a new era in biomedical field of research. Researchers synthesized novel materials that can be applied in the biomedical field specially for tumor detection and treatment. Co1−xMnxFe2O4 (x = 0.2, 0.4, 0.6, and 0.8) nano ferrites have been prepared by wet chemical co-precipitation method and coated by biocompatible material chitosan. Then the structure of the bare nanoferrite materials was confirmed by the XRD analysis that found that the material possesses a face-centered cubic (fcc) structure. The value of the experimental lattice constant was determined by analyzing the XRD data. For coated samples, Surface morphology was investigated by FESEM, both bright and dark TEM images, HRTEM and SAED images. The characteristic rings of the SAED pattern also define the fcc structure of the material which shows good agreement with XRD data. The calculated grain size found from the histogram of CoFe2O4 showed good agreement with the crystal size of the corresponding material. The proportions of the elements of bare and coated nanoferrites have been revealed by the EDS study. The successful coating was confirmed by FTIR spectra. Magnetic characterization of coated material was investigated by VSM. It has been seen that the sample Co0.8Mn0.2Fe2O4 showed the highest saturation magnetization and magnetic moment. For tumor treatments, the experimental value of hydrodynamic diameter and polydispersity index (PDI) of all the coated samples was within the permissible limit. Hyperthermia temperatures of the ferrite samples were calculated. From the time dependence temperature graph, using the sharp slope, the Specific Loss Power (SLP) value was also determined. By contrasting all the cytotoxicity data applied to the Hela cell line, cell viability has been observed at 95%. The values of Relaxivity were estimated from MRI images. With the rise of manganese ions, the value of relaxivities progressively decreased. Moreover, in-vivo angiography of the Albino Wistar rat was observed. Though chitosan-coatedferritesare not brain or muscle-specific, it has been observed that the contrast is enhanced for the images with agents than without agents. It is further observed that the contrast enhancement is the best with the contrast agent Co0.8Mn0.2Fe2O4.

High performance of the rare earth (Er, Gd & Pr) doped MoO3 thin films for advanced applications towards ammonia gas sensing

In this report, an economical spray pyrolysis technique was used to develop pure and 2% of Er, Gd, Pr doped MoO3 thin films. Different characterization techniques were utilized to study the properties of the pure and 2% of Er, Gd, Pr doped MoO3 thin films. The structural XRD analysis revealed monoclinic crystal structure of the MoO3 thin films with high purity and highest crystal size of 59 nm for the Pr doped MoO3 thin film. Furthermore, the lattice constant values increase with the substitution of Er, Gd, Pr dopants in MoO3 thin films. The morphological studies revealed reticulated nano-fibrous mesh morphology for all the samples and tiny rod-shaped protrusions over the surface of Pr doped MoO3 thin film. The optical studies demonstrated lower transparency, small bandgap and important defects. The gas sensing studies established the good response of the Pr doped MoO3 thin film towards the NH3 gas of 1.34 × 104% (250 ppm) with high stability and fast response (54 s) with a recovery time of 12 s. This opens door to our synthesized Pr doped MoO3 thin film materials to be used for the construction of commercial ammonia gas sensors.

Design of ultra compact 4:2 encoder using two dimensional photonic crystals

In this paper all optical ultra compact 4:2 encoder is proposed and designed using two dimensional photonic crystals (PC). The proposed structure has silicon rods of refractive index 3.4 embedded in air host by creating line defects in hexagonal lattice platform. The analysis of the design is done for various experimental values of radius, lattice constant and pitch values using finite difference time domain (FDTD) and plane wave expansion (PWE) method of licensed OptiFDTD software tool. The structure is optimised to get maximum power confinement at the output of the two ports of the 4:2 encoder by inserting extra rods which interns acts like a resonator to couple the power to the two output waveguides. The structure is chosen in such a way that ( $$\frac{a}{\lambda }$$ ) will fall around 1550 nm wavelength only and is good for long distance transmission application as it is having low attenuation constant and high contrast ratio. Further, the proposed 4:2 encoder is operated at 1550 nm and it provides a high contrast ratio of 9.25 dB, propagation delay 33.1 fs and foot print of the structure is 119.34 $$\mu$$ m $$^2$$ . Hence it is highly advisable for photonic integrated circuits and optical signal processing.

Band-gap engineering of rutile-structured SnO2−GeO2−SiO2 alloy system

Rutile-structured germanium oxide $(\mathrm{r}\text{\ensuremath{-}}{\mathrm{GeO}}_{2})$, an ultrawide band-gap (UWBG) semiconductor, is a promising candidate for future high-power electronics because of its excellent properties, including ambipolar dopability, high carrier mobilities, and a higher thermal conductivity than $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Ga}}_{2}{\mathrm{O}}_{3}$. In this paper, focusing on a wide variety of its applications, we propose an UWBG alloy system based on $\mathrm{r}\text{\ensuremath{-}}{\mathrm{GeO}}_{2}$ and other rutile-structured oxides $({\mathrm{SnO}}_{2}\text{\ensuremath{-}}{\mathrm{GeO}}_{2}\text{\ensuremath{-}}{\mathrm{SiO}}_{2})$ and clarify the electronic structure and electrical properties based on experiments and the first-principles calculations. Experimentally, (001)-oriented $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ alloy thin films with an entire range of Ge compositions $(x)$ were grown by a mist chemical vapor deposition technique. Structural characterizations show that the fabricated $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ alloy films with $x\ensuremath{\le}0.96$ and the well-crystallized part of the film with $x=1.00$ have uniform chemical compositions and the same epitaxial relations with $\mathrm{r}\text{\ensuremath{-}}{\mathrm{TiO}}_{2}$ (001) substrates. Transmission electron microscopy observations reveal that there are few dislocations in $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{0.66}{\mathrm{Sn}}_{0.34}{\mathrm{O}}_{2}$ because of relatively small in-plane lattice mismatch. In contrast, many dislocations are observed near the film/substrate interface in $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{0.96}{\mathrm{Sn}}_{0.04}{\mathrm{O}}_{2}$. Lattice constants of the alloys both along the $a$ and $c$ axes decrease with increase in Ge compositions. Their band gaps were determined by spectroscopic ellipsometry analysis, indicating that the band gaps increase as Ge compositions increase $(3.81\ensuremath{-}4.44\phantom{\rule{0.16em}{0ex}}\mathrm{eV})$ with a bowing parameter of 1.2 eV. The values of lattice constants and the trend of band-gap transitions obtained by calculations are in good agreement with those of experimentally obtained each other. Then we presented the calculated natural band alignments of $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ and $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ alloys, suggesting the possibility of $p$-type doping in $\mathrm{r}\text{\ensuremath{-}}{\mathrm{GeO}}_{2}$ and Ge-rich $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ and availability of $\mathrm{r}\text{\ensuremath{-}}{\mathrm{SiO}}_{2}$ and Si-rich $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ as a blocking layer of other rutile-structured devices. Finally, electrical measurements demonstrated $n$-type conductivities in $\mathrm{r}\text{\ensuremath{-}}{\mathrm{Ge}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}{\mathrm{O}}_{2}$ $(x\ensuremath{\le}0.57)$.

DFT Calculations Using Quantum ESPRESSO for Optical and Electronic Properties of Si Crystal

The DFT calculations were performed to study the structural, electronic and optical properties of Si. The open source computer code, Quantum ESPRESSO used is for first-principles electronic structure modeling based on density functional theory. The optimized crystal lattice constant, band gap, density of states (DOS) and band structure were calculated. The calculated value of lattice constant was in good agreement with reported value. The band gap was calculated using three different pseudo potentials. The HSE hybrid functional provided best agreement of band gap calculations with literature values. The pseudo-dielectric functions was also calculated to estimate the optical properties including refractive indices, extinction coefficients, reflectivities and absorption coefficients in the spectral energy ranges from 0 eV to 10 eV.

Lattice Dynamics, Mechanical Properties, Electronic Structure and Magnetic Properties of Equiatomic Quaternary Heusler Alloys CrTiCoZ (Z = Al, Si) Using First Principles Calculations.

First principles calculations are performed to investigate the thermodynamical stability, dynamical, mechanical, electronic and magnetic properties of CrTiCoZ (Z = Al/Si) novel quaternary Heusler alloys. A Y-type III atomic configuration is found to be the most stable structure for both compounds. The lattice constant values obtained using GGA-PBE approach are 5.9368 Å and 5.7853 Å for CrTiCoAl and CrTiCoSi, respectively. Using the value of elastic moduli for both the compounds, the computed Pugh’s ratio value is 2.5 and 2.7 for CrTiCoAl and CrTiCoSi, respectively, which is higher than 1.75, indicating both the compounds are ductile in nature. The melting temperatures of both compounds are as high as 2142 K and 2420 K for CrTiCoAl and CrTiCoSi, respectively. The electronic structure calculations, using the GGA-PBE approach, show a half metallic behavior of CrTiCoAl. The spin-down channel exhibits a direct band gap of 0.15 eV, whereas the spin-up channel is metallic, making CrTiCoAl a half metallic ferromagnet with 100% spin polarization and an appreciable magnetic moment of −2 μB. However, CrTiCoSi is found to be semi-metallic in the spin-down channel and metallic in the spin-up channel, which leads to a spin polarization of 99.7% with a non-integer magnetic moment of −0.99 μB. The Curie temperature of CrTiCoAl is well above the room temperature (385 K), whereas that of CrTiCoSi is below the room temperature (203 K). Thus, CrTiCoAl is found to be more promising than CrTiCoSi as a spin injector in spintronic devices.

Co‐Doping Strategies to Improve the Electrochemical Properties of LixMn2O4 Cathodes for Li‐Ion Batteries

AbstractFour novel cathode electrode materials with improved material properties have been derived from the Lithium Manganese Oxide spinel using co‐doping strategies. Specifically, Aluminum, Nickel, Magnesium, and Yttrium were selected as the primary dopant to replace a fraction of Mn3+ (5 %), and S2− was selected as the secondary dopant to replace 1 % of O2−. A combination of quantum mechanics and molecular dynamics was used to study the fracture mechanics of the new materials for various State of Charge values, and improved performance is validated with experimental data. The results show that lattice constant values for all the doped structures decrease by 1.87 %–2.07 %. Overall, with co‐doping, the diffusion properties improved, and activation energy required for Li+ vacancy migration reduced (0.21–0.25 eV). We conclude that with reduced inter‐atomic distance, the overall life of the LMO spinel can be improved. The Computational Fluid Dynamics simulations to study the macro‐scale behaviour of these new materials shows a reduction in intercalation induced stress and heat generation.

Growth, physicochemical and optical properties of LuYSGG garnet single crystal

We investigate the physical and chemical properties of a Lu1Y2Sc2Ga3O12 (LuYSGG) single crystal with high quality grown by the Czochralski (Cz) method. The XRC result shows the crystal has high crystalline quality and the lattice constant is calculated to be 12.4253 Å, and the lattice constant value could be adjusted by changing the ratio of Lu and Y. The dislocation density on the (111)-crystalline face is achieved to be about 200 cm−2. The Mohs hardness is obtained to be 6.86. The surface roughness (Ra) of the polished LuYSGG wafer is only 0.23 nm. The thermal expansion coefficient and the thermal conductivity are measured to be 8.5 × 10−6 K−1 and 4.79 W m−1 K−1, respectively, indicating the LuYSGG has better thermal properties. In addition, the Sellmeier equation is fitted by the measured refractive indices at a few distinct wavelengths using the method of minimum deviation angle, and the refractive index curve in the range of 400–3000 nm is displayed. The maximum phonon energy of LuYSGG crystal is determined to be 880.7 cm−1. All the obtained results can provide useful reference parameters for the further investigation of LuYSGG crystal as epitaxial magneto-optical thin film substrate and laser host.

Structural and optical behavior of gallium and cobalt co-doped ZnO thin films fabricated by a sol-gel spin coating technique

In this study, the ZnO thin films with varying Ga/Co co-doping concentrations were produced on the quartz substrates by spin-coating technique. The structural and optical behavior of the films were analyzed by X-ray diffraction (XRD) and UV–Vis spectroscopy, respectively. XRD results reveal that all the films possess a hexagonal wurtzite structure of ZnO and have crystallite sizes in the range 8–24 nm. The prominent peaks (relative intensity greater than 10%) observed in the XRD profiles correspond to (100), (002), (101) and (103) planes, whereas the most preferred orientation of crystal growth in all the films is (002) plane. A small variation in the lattice constant values has been found owing to the inclusion of dopants and co-dopants in the ZnO lattice, as well as defects created in the crystal lattice at the time of film growth. Compared to the undoped ZnO film, the optical transmittance improves beyond the 430 nm wavelength upon 1 at% Ga doping, while in (1 at% Ga + 1 at% Co) and (3 at% Ga + 1 at% Co) co-doped films, it improves beyond the 600 nm wavelength. The UV–Vis spectroscopy results show the optical band gap value of 3.28 eV for the undoped ZnO film, which changes by a small amount in the doped and co-doped films.

Применение meta-GGA функционала scan к расчету поверхностных свойств Pd и IR

The results of first-principles calculations of the structural and surface characteristics of palladium and iridium using the VASP software package with the Meta-GGA SCAN functional are presented. The calculations of the lattice constant values for bulk metals Pd and Ir for various PBE and SCAN functionals showed the best convergence and agreement with the experimental values when using the SCAN functional. The values of the surface energy and the work function of an electron from the surface of a Pd and Ir plate with a thickness of 1 to 10 monolayers were calculated taking into account relaxation for various orientations of the surface face (100), (110), (111). Smaller error and better agreement with experimental values was obtained using the SCAN functionality, especially for palladium. The values obtained for different orientations of the surface face satisfy the relation: σ110 > σ100 > σ111. The most close-packed face has the lowest surface energy.

Structural, Morphological, and Dielectric Evaluation of Co2+ Doped Zinc Ferrite Aluminate

AbstractCobalt substituted zinc ferrite aluminate series with compositional formula Zn1‐xCoxFeAlO4 (x = 0.0, 0.2, 0.4, and 0.6) is prepared by chemical sol–gel synthesis. The prepared samples are characterized by X‐ray diffraction (XRD), transmission electron microscope (TEM) technique. A cubic spinel phase is revealed by XRD analysis and confirmed from selected area electron diffraction (SAED) pattern. The true values of lattice constant are obtained from Nelson–Riley extrapolation plot, and lattice strain values are obtained with the help of Williamson‐Hall equation. The TEM image confirms average crystallite size of 31 nm. The dielectric study discloses the decrease of dielectric constant and loss tangent with the increasing frequency of applied field.

Optical, Structural, Morphological Properties of Chromium (III) Oxide Nanostructure Synthesized Using Spray Pyrolysis Technique

Nanostructure of chromium oxide (Cr2O3-NPs) with rhombohedral structure were successfully prepared by spray pyrolysis technique using Aqueous solution of Chromium (III) chloride CrCl3 as solution. The films were deposited on glass substrates heated to 450°C using X-ray diffraction (XRD) shows the nature of polycrystalline samples. The calculated lattice constant value for the grown Cr2O3 nanostructures is a = b = 4.959 Å & c = 13.594 Å and the average crystallize size (46.3-55.6) nm calculated from diffraction peaks, Spectral analysis revealed FTIR peak characteristic vibrations of Cr-O Extended and Two sharp peaks present at 630 and 578 cm-1 attributed to Cr-O “stretching modes”, are clear evidence of the presence of crystalline Cr2O3. The energy band gap (3.4 eV) for the chromium oxide nanostructures was measured using the UV-VIS-NIR Optical Spectrophotometer. It was found that by scanning electron microscopy (SEM) and image results, there is a large amount of nanostructure with an average crystal size of 46.3-55.6 nm, which indicates that our synthesis process is a successful method for preparing Cr2O3 nanoparticles.

Structural and Elastic Properties of Pd2CrPb Heusler Compound

Electronic, structural and elastic properties of Pd2CrPb compound were examined with Density Functional Theory (DFT). The lattice constant in state of balance and the total magnetic moment value were calculated and 6.454 A0 and 3.678 µB f.u. values were obtained respectively. The lattice constant and total magnetic moment value obtained for Pd2CrPb compound were compared to existing values in the literature, and the results obtained were found to be consistent with the literature results. The calculation of bulk modulus in this study is non-existent in the literature. The bulk modulus of this molecule is presented in the literature in this sense. The aim of the study is to publish the results of studies on non-existent electronic, structural and elastic properties for Pd2CrPb compound conducted using density functional theory. The electronic band structure, total and partial density graphs for Pd2CrPb compound were drawn. Bulk modulus (B), Shear modulus (G), B/G ratio, Young modulus (E), Poisson ratio, C11, C12 and C44 values were also calculated for this compound. Pd2CrPb compound meets Born stability principles and calculated elastic stabilities show that this compound is mechanically stable.

Formation of Solid Solutions and Physicochemical Properties of the High-Entropy Ln1-xSrx(Co,Cr,Fe,Mn,Ni)O3-δ (Ln = La, Pr, Nd, Sm or Gd) Perovskites.

Phase composition, crystal structure, and selected physicochemical properties of the high entropy Ln(Co,Cr,Fe,Mn,Ni)O3−δ (Ln = La, Pr, Gd, Nd, Sm) perovskites, as well as the possibility of Sr doping in Ln1−xSrx(Co,Cr,Fe,Mn,Ni)O3−δ series, are reported is this work. With the use of the Pechini method, all undoped compositions are successfully synthesized. The samples exhibit distorted, orthorhombic or rhombohedral crystal structure, and a linear correlation is observed between the ionic radius of Ln and the value of the quasi-cubic perovskite lattice constant. The oxides show moderate thermal expansion, with a lack of visible contribution from the chemical expansion effect. Temperature-dependent values of the total electrical conductivity are reported, and the observed behavior appears distinctive from that of non-high entropy transition metal-based perovskites, beyond the expectations based on the rule-of-mixtures. In terms of formation of solid solutions in Sr-doped Ln1−xSrx(Co,Cr,Fe,Mn,Ni)O3−δ materials, the results indicate a strong influence of the Ln radius, and while for La-based series the Sr solubility limit is at the level of xmax = 0.3, for the smaller Pr it is equal to just 0.1. In the case of Nd-, Sm- and Gd-based materials, even for the xSr = 0.1, the formation of secondary phases is observed on the SEM + EDS images.

New isostructural halide double perovskites Cs2GeNiX6 (X= Cl, Br) for semiconductor spintronics and thermoelectric advancements

The depletion of fossil fuels and tremendous increase in environmental pollution in the current era has turned the attention of the world's scientists to explore renewable alternative energy resources. Within the first principle calculations, from the Density Functional Theory (DFT) a compact overview on various physical properties of halide perovskites Cs2GeNiX6 (X ​= ​Cl, Br) has been summed up. The obtained values of relaxed lattice constants from the well-known Birch-Murnaghan equation and bond lengths are identical with previously reported values. The calibration of sophisticated Hubbard potential (GGA ​+ ​U) claims Cs2GeNiX6 (X ​= ​Cl, Br) have semiconducting nature with a total magnetic moment of 2 ​μB. Elastically and mechanically alloys are characterized to be stable via checked from their respective cubic elastic packages which display brittle/ductile strength. The flexibility of these perovskite structures suppresses the lattice thermal conductivity, which promotes an exclusive thermoelectric response. The occurrence of such properties in these layered structures lends their broad range of applications in semiconductor spintronics and power technology sources.

Effects of Gum Arabic-Coated Magnetite Nanoparticles on the Removal of Pb Ions from Aqueous Solutions

To study the removal of lead (Pb) ions from aqueous solutions, novel magnetite nanoparticles (NPs) of Ni0.31Mg0.15Ag0.04Fe2.5O4 were synthesized by coprecipitation synthesis using metal sulfates, and then coated with Gum Arabic (GA). The prepared NPs were analyzed using various spectroscopic and analytical methods, such as X-Ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infra-Red spectroscopy (FT-IR), and Atomic Absorption Spectrophotometer (AAS). By using XRD analysis, the cubic inverse spinel structure of the prepared NPs was proven, showing average values of crystallite size, lattice constant, and density of 28.57nm, 8.32582Å, and 5.2890 g/cm3, respectively. FE-SEM analysis revealed the sphere-like shape of the nanoparticles with a measured crystallite size of 25.93nm. The existence of constituent elements was evidenced by EDX. FT-IR test proved the success of the coating process of magnetite NPs by the presence of the main characteristic absorption bands of GA in the FT-IR spectrum of GA-magnetite NPs. The adsorption of Pb ions by GA- magnetite NPs was shown by AAS analysis, where the concentration of Pb ions decreased from 25ppm to 6.6ppm, reaching 1.1ppm at the time of 25min. The porosity of the NPs and the carboxyl groups in GA played an important role in the process.