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The present article has utilized the WIEN2k computational code to examine the structural, elastic, electronic, magnetic, thermoelectric, and dynamic aspects of the CoCrS Half-Heusler (HH) compound. In this work, calculations have been performed by utilizing the full-potential linearized augmented plane wave method using density functional theory. The electronic bandgap was better interpreted by using the modified Becke–Johnson exchange–correlation functional. We evaluated various electronic properties of the CoCrS HH compound, including band structure plots and density of states. Furthermore, we examined the magnetic characteristics through the computation of magnetic moments and the examination of the spin-polarized electronic state behavior. We also determined the elastic properties of the CoCrS HH compound. These properties, which include stiffness, resilience, and general stability, provide important information about how the material responds to mechanical deformation. Moreover, we explored the electronic structure and found that type 5 of CoCrS exhibits a metallic behavior. In addition, we examined the compound’s thermoelectric properties. Finally, the dynamical properties indicate that type 5 of CoCrS is dynamically stable.

Green technique or chemical co-precipitation technique has been employed to synthesize the MgZnFe2O3, CoZnFe2O3 and NiZnFe2O3 quaternary alloys nanoparticles. The structural properties are investigated by X-ray diffraction (XRD) to determine structural parameters and crystallite size. XRD peaks index numbers and intensities are varied with the atomic number. The study of morphology for the mentioned quaternary alloys nanoparticles is analyzed by scanning electron microscopy (SEM) to measure the grain size. The optical properties are investigated via ultraviolet–visible (UV–vis) and Fourier-transform infrared spectroscopy (FTIR) to reveal the changing of absorption, transmission, reflection and bandgap as the atomic number changes for verifying optical dielectric constant and refractive index models. The obtained results suggest that MgZnFe2O3, CoZnFe2O3 and NiZnFe2O3 quaternary alloys nanoparticles are very suitable for potential application in optoelectronics and antibacterial treatment.

The benefits of the electrical-based biosensor include cheap production and fast response time of detecting diseases. An interdigitated electrode (IDE) is fabricated using silver (Ag) as a metal contact that is deposited on aliminium (Al) nanoparticles doped with both zinc oxide (ZnO) and Silicon (Si) forming AZO/Si nanostructures by vacuum coater in a thermal evaporator. The electrical properties are studied as a function of frequency and voltage using I–V characteristics. Sol–gel method under annealing temperature, 500 °C is utilized to generate Al nanoparticles doped ZnO nanostructures. UV–vis spectrophotometer, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD) are used for analyzing optical, topographical, morphological and structural studies of AZO nanostructure, respectively. Specific empirical models of optical dielectric constant, bulk modulus and refractive index are also verified. PACS: 75.75.Fk, 77.55.hf, 87.85.fk, 88.10.gp, Keywords: AZO, Sol–gel method, Characterization, Optical

In this work, two kinds of competition between different Heusler structure types are considered, one is the competition between XA and L21 structures based on the cubic system of full-Heusler alloys, Pd2YZ (Y = Co, Fe, Mn; Z = B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, Sb). Most alloys prefer the L21 structure; that is, Pd atoms tend to occupy the a (0, 0, 0) and c (0.5, 0.5, 0.5) Wyckoff sites, the Y atom is generally located at site b (0.25, 0.25, 0.25), and the main group element Z has a preference for site d (0.75, 0.75, 0.75), meeting the well known site-preference rule. The difference between these two cubic structures in terms of their magnetic and electronic properties is illustrated further by their phonon dispersion and density-of-states curves. The second type of competition that was subjected to systematic study was the competitive mechanism between the L21 cubic system and its L10 tetragonal system. A series of potential tetragonal distortions in cubic full-Heusler alloys (Pd2YZ) have been predicted in this work. The valley-and-peak structure at, or in the vicinity of, the Fermi level in both spin channels is mainly attributed to the tetragonal ground states according to the density-of-states analysis. ΔEM is defined as the difference between the most stable energy values of the cubic and tetragonal states; the larger the value, the easier the occurrence of tetragonal distortion, and the corresponding tetragonal structure is stable. Compared with the ΔEM values of classic Mn2-based tetragonal Heusler alloys, the ΔEM values of most Pd2CoZ alloys in this study indicate that they can overcome the energy barriers between cubic and tetragonal states, and possess possible tetragonal transformations. The uniform strain has also been taken into consideration to further investigate the tetragonal distortion of these alloys in detail. This work aims to provide guidance for researchers to further explore and study new magnetic functional tetragonal materials among the full-Heusler alloys.

We report results of first-principles calculations for the structural, mechanical, dynamical and electronic properties of Scandium Carbide (ScC) compound, using a Full-Potential Linearized-Augmented Plane Wave (FP-LAPW) method based on density functional theory, within the generalized gradient approximation (GGA). The computed ground states properties; lattice constants, bulk modulus and the pressure derivative of the bulk modulus (a0, B and B') are in good agreement with former works. The calculated transition pressures from the rocksalt (NaCl) structure to the CsCl structure and from the NiAs to CsCl are found to be 111.0 GPa and 27.15GPa, respectively. It was found, that NaCl and NiAs are mechanically and dynamically the stable phases, with NaCl considered as the ground state phase. In contrast, the Zincblende (ZB) and CsCl are both unstable phases mechanically and dynamically. Wurtzite (WZ) phase was found mechanically stable and dynamically not, which might be a possible indication for a metastable phase. The electronic structures reveal that all the considered structures have a metallic character. Upon our best knowledge, for the first time, the mechanical and dynamical properties of the studied structures beside NaCl were calculated.

First-principles calculations using the plane-wave pseudopotential method within the generalized gradient approximation method were performed to study the pressure dependence of the structural, elastic, electronic and optical properties for the half-Heusler compounds ScPtSb and YPtSb in a cubic MgAgAs-type structure. The calculations were performed with the inclusion of spin-orbit coupling. The calculated equilibrium lattice parameters are in good agreement with the available experimental and theoretical values. The crystal rigidity and mechanical stability were discussed using the elastic constants and related parameters, namely bulk modulus, shear modulus, Debye temperature, Poisson's coefficient, Young's modulus and isotropic sound velocities. The calculated electronic band structures show that ScPtSb has an indirect gap of Γ-X type, whereas YPtSb has a direct band gap of Γ-Γ type. Furthermore, the effect of pressure on the optical properties, namely the dielectric function, absorption spectrum, refractive index, extinction coefficient, reflectivity and energy-loss spectrum is investigated for both compounds ScPtSb and YPtSb.

Zinc oxide has been synthesized using sol-gel method with different Al nanoparticles (40, 70 and 100 nm). It has been analysed and characterized by UV–vis, X-ray diffraction (XRD), atomic force microscopy (AFM) and Scanning Electron Microscopy (SEM), respectively. It has been revealed that Al nanoparticles (Al NPs) affect ZnO’s particle size, thickness, roughness, bulk modulus, energy gap, absorbance and transmittance. The optical band gap is varied with Al nanoparticles. The bulk modulus has been calculated to investigate the stiffness of AZOs. Our measured values are in good agreement with other data available in the literature. Keywords: ZnO, Nanoparticles, Analysis, Characterization

Through first-principles calculation based on the density functional theory (DFT) within the pseudo potential-plane wave (PP-PW) approach, we studied the structural, mechanical and thermal properties of Cu2CdSnSe4 and Cu2HgSnSe4 adamantine materials. The calculated lattice parameters are in good agreement with experimental and theoretical reported data. The elastic constants are calculated for both compounds using the static finite strain scheme. The hydrostatic pressure action on the elastic constants predicts that both materials are mechanically stable up to 10 GPa. The polycrystalline mechanical parameters, i.e., the anisotropy factor (A), bulk modulus (B), shear modulus (G), Young's modulus (E), Lame's coefficient (λ) and Poisson's ratio (ν) have been estimated from the calculated single crystal elastic constants. The analysis of B/G ratio shows that the two studied compounds behave as ductile. Based on the calculated mechanical parameters, the Debye temperature and the thermal conductivity have been probed. In the framework of the quasi-harmonic approximation, the temperature dependence of the lattice heat capacity of both crystals has been investigated.

The structural, elastic, electronic, and magnetic properties of the CrCoSi, MnCoSi parent half-Heusler (HH) alloys, and their CrMn[Co.sub.2][Si.sub.2] derivative double half-Heusler (DHH) compound are studied, utilizing the augmented plane wave method, which is based on density functional theory and implemented in the WIEN2k code. The stability of HH structure of the CrCoSi and MnCoSi alloys has been checked for their non-magnetic and ferromagnetic phases, leading to that the latter phase of the type I arrangement is the most stable. The CrMn[Co.sub.2][Si.sub.2] DHH alloy, derivative from the found structural and magnetic ground states of CrCoSi and MnCoSi HH alloys, is constructed and investigated. This DDH as well as its CrCoSi parent HH are found to be resistant to deformation and can be classified as ductile materials, whereas the MnCoSi compound is brittle. By the gradient generalized approximation (GGA), the electronic structures of CrCoSi, MnCoSi, and CrMn[Co.sub.2][Si.sub.2]compounds exhibit a metallic behavior in the spin-up channel and a semiconducting behavior in the spin-dn channel, with band gaps (half-metallic gaps) of 0. 851(0.020), 0.852(0.021), and 0.531(0.002) eV, respectively. The half-metallicity of CrMn[Co.sub.2][Si.sub.2] DHH is retained with smaller (larger) band gap (half-metallic gap) of 0.38(0.106) eV than that of GGA, using GGA + U approximation. In addition, the total magnetic moments are found to be 1, 2, and 3 [[mu].sub.B] for CrCoSi, MnCoSi, and CrMn[Co.sub.2][Si.sub.2], respectively. Therefore, these alloys can be good candidates for spinitronic applications due to their half-metallicity. Key words: half-metal, heusler alloys, spin polarization, mechanical stability, FP-LAPW, 1. Introduction Spin-based electronics has grown into a significant field of study that spans a wide range of high spin-polarized materials, used in spintronic devices. It overcomes the limitations of [...]