Papers by Keyword: Structural Properties

Abstract: Thermoelectric materials are useful for various application in daily life. Their application such as sensors, generators and electronic components, making thermoelectric materials widely studied. Antiperovskite compounds that can have semiconducting behaviour is probable candidate for thermoelectric materials. In this article, thermoelectric properties of anti-perovskite X₃SiO (X = Sr and Ba) were investigated using density functional theory (DFT) method and Boltzmann Transport Equations (BTE). Electronic properties such as band structure, partial density of states were computed using the generalized gradient approximation with Perdew-Burke-Ernzerhof (GGA-PBE) functional in CASTEP code. The thermoelectric properties such as Seebeck coefficient, electrical conductivity, and power factor are calculated using BoltzTraP code that utilised BTE. The calculated band structures of Ba₃SiO and Sr₃SiO show that these compounds having semiconductor behaviour with direct band gap of 0.44 and 0.43 eV respectively at Γ-Γ k-point. It was found that Ba₃SiO is a better candidate for thermoelectric materials due to its higher Seebeck coefficient (-4.90 10^-4 V/K) at room temperature compared to calculated Seebeck coefficient (-5.84 10^-4 V/K) of Sr₃SiO. The power factor value of Ba₃SiO which is 2.96 x 10^-4 W/mK² is also higher compared to power factor of Sr₃SiO at 7.12 x 10^-7 W/mK² at room temperature.

Abstract: Ceramic Metallic Alloys of TiC/Ni, Comprising Titanium Carbide with Nickel Contents of 5%, 15%, 30%, and 50%, were Fabricated through Solid-Phase Sintering at 1400°C with a 2-hour Holding Time and a Pressure of 50MPa. This Study Explores the Impact of Nickel Content on the Mechanical and Structural Properties. The Solidification Mechanism between TiC and Ni is Governed by Carbon Diffusion through TiC Particles, Affecting the Morphology of TiC and Carbon Particles in Ni Samples. The Reaction Behavior within the TiC/Ni Alloys was Analyzed, and Microstructural and Mechanical Characteristics were Examined to Evaluate the Influence of Varying Nickel Contents. Results indicate that in all samples, the TiC matrix exhibited a solid solution of the FCC phase. The reaction mechanism of Ti-C-Ni reveals the evolution of solid phase formation with increasing nickel content. As nickel content increases, the mass and size of nickel particles grow, leading to a more uniform and homogeneous structure. At a nickel content of 15%, the samples displayed a bending strength of 1200 ± 50 N, a microhardness of 800 ± 20 (HV _0.1), and a density of 5.6 ± 0.2.

Abstract: This article presents, the systematic and successful preparation of cadmium substituted cobalt ferrite (Co_1-xCd_xFe₂O₄) nanoparticles via simple co-precipitation method. X-ray diffraction study confirmed the prepared ferrite nanoparticles were crystallized with a mono phase cubic spinel structure of Fd3m space group. The average crystallite size (D_xrd) was increased with Cd doping content, due to the replacement of Co²⁺ ions by Cd²⁺ ions. XRD pattern revealed the high intense peak corresponds to (311) lattice plane and confirmed the formation of cubic structure ferrite nanoparticles. Morphological study was done by using SEM images. The grain size found to be increased with Cd concentration and it reaches the highest of around 0.9μm for Co_0.52Cd_0.48Fe₂O₄ composition. Fourier Transform Infrared spectroscopy of prepared samples was recorded in the range of 1000-350 cm^-1, confirmed the spinel structure.

Abstract: The combined of superparamagnetic properties (magnetite) and surface characteristics (silica), can produce structures with multiple capacities. The preparation of such magnetite-silica core-shell nanoparticles involves high costs in their execution and longer time. In this work, Fe₃O₄@SiO₂ CSNPs were synthesized in two stages to control their size and the possibility of adjusting their characteristics. First, Fe₃O₄ NPs were synthesized by a green method using carob leaf extract, then coating the magnetite nanoparticles with a silica layer was done by using Tetraethylorthosilicate (TEOS) as a silica precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscope (AFM), Fourier transform infrared, and vibrating sample magnetometer techniques were used to characterize the magnetite-silica CSNPs. TEM images confirms that Fe₃O₄NPS and Fe₃O₄@SiO₂ CSNPs synthesized had a spherical shape and were within 9 and 17 nm. The average crystallite sizes of the synthesized Fe₃O₄ NPs and Fe₃O₄@SiO₂CSNPs were found to be 17.8 nm and 20 nm. The VSM indicated that the magnetization decreased due to being coated with silica.

Abstract: Copper Zinc Sulfide Cu_xZn_yS (CZS) thin films with different thicknesses were prepared by the ultrasonic spray pyrolysis method (USP). The influence of deposition time on the structural, morphological, and optical properties of the thin films has been investigated. XRD styles revealed the formation of ternary CZS films. Synchrotron X-ray diffraction measurements confirmed the presence of the two phases CuS and ZnS, which form the ternary compound CZS. Crystallite size increases from 75.29 nm to 105.46 nm as deposition time increases whereas the strain parameter decreases from 6.27*10^-4 to 3.28*10^-4. The obtained SEM images show that CZS thin films have a dense and rough surface topography. Spectrometric analysis of the deposited films confirmed the alloy nature of the elaborated films, whereas the corresponding values of band gaps were in the range of 3.28 to 3.17 eV. Results show that increasing the deposition time enhances the optical properties. Furthermore, the electrical properties of CZS films are influenced by the deposition time and phase transition. Significant improvements on these properties were obtained when the thin film thickness increased: the resistivity decreased from 95.10 to 0.12 Ω cm the carrier centration increased from 4.03×10²¹ to 14.07×10²¹ cm⁻³ and the mobility varied from 0.83 to 18.75 cm² V⁻¹ S⁻¹.

Abstract: In the past few decades Aluminium alloys have been extensively used in most of the structural applications, where there is a need to reduce weight and substantially providing structural strength and stability to the assembly. Aluminium alloys or Titanium alloys are the best possible options for the design engineers to select over alloy steel for structural applications when mass reduction is an important factor, However Aluminium alloys wins the race over Titanium alloys when cost is an important criteria for selection of materials. Aluminium alloys are chosen as an alternative next to titanium alloys when it comes to high strength to weight ratio. Titanium alloys particularly Ti6Al4V is selected for applications where the component is loaded with high temperature. Therefore engineers have to evaluate the loading conditions and its environment based on the properties of alloys for selection of Aluminium alloys over other alloys for structural applications. Material selection for the structural applications in various industries such as aerospace, automotive, Industrial and construction sector are based on its function, which depends on the factors like the loading conditions, environment, and functional requirements. The main strength requirements for structural applications are its mechanical properties namely Tensile strength either compressive or tensile load, The present review is to study and understand the characteristics of Aluminium alloys and ways to enhance the mechanical properties of Aluminium alloys.

Abstract: Indium tin oxide (ITO) thin films with 100 nm thickness were successfully deposited on soda-lime glass substrates by metal oxide electron beam evaporation at room temperature. The deposited films were post annealed via rapid thermal processor (RTP) in vacuum environment at 400 to 550 °C. All deposited ITO thin films were studied on the structural, electrical, and optical properties. Results showed that the post annealing treatment by RTP improved the crystallinity, increased crystallite size, and increased surface roughness values. Higher RTP post annealing temperature also enhanced the electrical performance that led to higher transmittance of ITO thin films.

Abstract: Nanostructured FeNi and FeNiGr alloys were successfully synthesized by the mechanical alloying technique. The alloys formation and different magnetic properties were studied as a function of milling time in the range of 0 to 30h by X-ray diffraction (XRD) technique, Scanning Electron Microscope (SEM) analysis and a Vibrating Sample Magnetometer (VSM) process. The X-ray diffraction study confirmed the apparition of the α-FeNi alloy after 5h of milling with an average crystallite size of 26.80nm. The crystallite size obtained after 30h of milling is 10.13nm, While, the lattice deformation increases from 0.431 to 0.935%. in addition, the analysis of the magnetization curves of the Fe-Ni alloys revealed original magnetic properties: super paramagnetic behavior, and especially saturation magnetization and significant coercivity. ​​​​​​​ Furthermore, the addition of graphene into FeNi alloy, reduced its crystallite size from 11.56 to 6.65 nm, and increases the lattice strain and lattice parameter from 0.631 to 0.748% and from 0.28686 to 0.28704nm, respectively. Which, enhanced these magnetic properties, by increasing its coercivity (Hc) from 16. 07 to 135.42 Oe and Mr from 1.73 to 5.87 emu/g, while the magnetization saturation is decreased from 153.25 to 123.06 emu/g.

Abstract: This study includes the preparation of the ferrite nanoparticles Cu_xCe_0.3-XNi_0.7Fe₂O₄ (where: x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) using the sol-gel (auto combustion) method, and citric acid was used as a fuel for combustion. The results of the tests conducted by X-ray diffraction (XRD), emitting-field scanning electron microscopy (FE-SEM), energy-dispersive X-ray analyzer (EDX), and Vibration Sample Magnetic Device (VSM) showed that the compound has a face-centered cubic structure, and the lattice constant is increased with increasing Cu ion. On the other hand, the compound has apparent porosity and spherical particles, and there are no other elements other than those participating in the preparation of the compound, which means that it is of high purity. The prepared compound possesses excellent magnetic properties due to the narrowness of the magnetic hysteresis ring. The gas sensing system found that the compound has good sensitivity to H₂S gas.

Abstract: A single-step of pulsed laser deposition method was used to manufacture (Cu₂O) cuprous oxide nanothin films on Silicone substrates at low growing temperature in this study. The effects of three parameters of pulsed laser energies (800-1200 mJ) was used to explored in order to maximize the structural and morphological quality. (XRD) X-ray diffraction, Scanning electron microscopy with field emission (FESEM), and Atomic force microscopy were used to evaluate the effects of laser pulsed energies on the characteristics of Cu₂O nanofilms (FESEM). When compared to a crystalline silicon surface, the results of AFM show a higher possibility of better absorption and hence lower reflection.