East European Journal of Physics最新文献

{"title":"Enhancements of Structural and Optical Properties of MgO: SnO2 Nanostructure Films","authors":"R.H. Ayoub, Muhammad H. AL-Timimi, M.Z. Abdullah","doi":"10.26565/2312-4334-2023-3-64","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-64","url":null,"abstract":"This study investigates the structural and optical properties of MgO:SnO2 nanoparticles using the Chemical precipitation method, The thin films were deposited by the spin coating technique on glass substrates. X-ray diffraction analysis proved the crystalline structure of prepared thin films, with the peaks corresponding to the (110), (101), (200), (211), and (220) planes, with the tetragonal SnO2 crystal structure, Fourier transforms infrared (FTIR), and scanning electron microscope (SEM) used to characterize the functional groups, shape, and dimensions of synthesized metal oxide nanoparticles. The optical properties of the films were studied by UV-Vis spectroscopy, and the bandgap energy was estimated to be in the range of (3.9 - 3.4 eV). The refractive index and extinction coefficient of the films were also determined, and the results indicated that the films had good transparency in the visible region, The study concludes that MgO:SnO2 thin films obtained by spin coating technique have potential applications in optoelectronics and gas sensors.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Quantum Confinement Energy on the Transmittance of Cadmium Telluride (CdTe) Within the Near Infrared Region (700-2500nm)","authors":"Ali Hussein Hammad Asal, Saeed Naif Turki Al-Rashid","doi":"10.26565/2312-4334-2023-3-33","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-33","url":null,"abstract":"This study investigates how the energy of quantum confinement affects the transmittance of cadmium telluride, because of the importance of this substance, as it crystallizes in the form of cubes as thin films that are used in solar cells and liquid crystal imaging devices, as well as in infrared optics [1]. The MATLAB computer program version (2012a) was used, which is based on the characteristic matrix theory and Brus model, in addition to the quantum confinement energy equation. We found that the transmittance value of the nano CdTe thin film at normal incidence reaches 96.4% at a quantum confinement energy Eco = 2.7eV and at a particle size PS =2.6nm, while the value reaches 73.6% at a quantum confinement energy Eco = 0.01eV and at a particle size of PS=50nm.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of O-Mode in the Presence of Ion-Cyclotron Drift Wave Turbulence in a Nonuniform Plasma","authors":"Banashree Saikia, P.N. Deka","doi":"10.26565/2312-4334-2023-3-09","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-09","url":null,"abstract":"This study aims to investigate the effect of ion-cyclotron drift wave turbulence on the generation of ordinary mode (O-mode) in the presence of density and temperature gradients. For this, a Vlasov plasma is considered where a resonant, and non-resonant modes are considered to be present in the system. Here, the non-resonant mode is a perturbation caused by O-mode in a quasi-steady state of plasma, which is characterised by the presence of low frequency ion-cyclotron resonant mode waves. The interaction between these waves is studied by the Vlasov-Maxwell set of equations and a modified Maxwellian-type distribution function for particles that includes the external force field and associated density and temperature gradient parameters . The study analyses the growth rate of electromagnetic O-mode at the expense of ion-cyclotron drift wave energy and the associated impact of the density and temperature gradient. This model uses the linear response theory on weakly turbulent plasma, evaluates the responses due to turbulent and perturbed fields, and obtains the nonlinear dispersion relation for O-mode.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permittivity Model Selection Based on Size and Quantum-Size Effects in Gold Films","authors":"Beloshenko, Konstantin, Riabenko, Iuliia, Shulga, Sergey, Makarovskii, Nikolai","doi":"10.26565/2312-4334-2023-3-44","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-44","url":null,"abstract":"The article is focused on optical properties of nanostructures containing spherical gold nanoparticles of various radii. We explore correlation between the particle radius and the choice of permittivity model applied to describe optical absorption spectra of gold granules. The experiments show splitting of the absorption band of granular gold films to form a second absorption peak. The first peak is associated with the phenomenon of plasmon resonance, while the second one reflects quantum hybridization of energy levels in gold. Quantum effects are shown to prevail over size effects at a granule diameter of about 5-6 nm. The Mie theory gives a rigorous solution for the scattered electromagnetic field on a sphere taking into account optical properties of the latter, however, it does not specify the criteria for selecting a model to calculate dielectric permittivity. Both calculations and experiments confirm the limiting diameter of gold nanoparticles where the Hampe-Shklyarevsky model is applied. Meanwhile, this model is still unable to predict the splitting of the plasma absorption band. The data presented in the article can be used for a predetermined local field enhancement in composite media consisting of a biolayer and metal nanoparticles. The conducted research provides a deeper understanding of the influence of a terahertz high-intensity electromagnetic field localized in the space on quantum dots.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135369357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the Effect of Gravity Modulation on Weakly Nonlinear Magnetoconvection in a Nonuniformly Rotating Nanofluid Layer","authors":"Michael I. Kopp, Volodymyr V. Yanovsky","doi":"10.26565/2312-4334-2023-3-18","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-18","url":null,"abstract":"This paper investigates the impact of gravity modulation on weakly nonlinear magnetoconvection in a nanofluid layer that is nonuniformly rotating. The fundamental equations are obtained for the Cartesian approximation of the Couette flow using the Boussinesq approximation and gravitational modulation. The weakly nonlinear regime is analyzed using the method of perturbations with respect to the small supercritical parameter of the Rayleigh number, considering the effects of Brownian motion and thermophoresis in the nanofluid layer. Heat and mass transfer are evaluated in terms of finite amplitudes and calculated from the Nusselt numbers for the fluid and the volume concentration of nanoparticles. The findings demonstrate that gravitational modulation, nonuniform rotation, and differences in the volume concentration of nanoparticles at the layer boundaries can effectively control heat and mass transfer. Additionally, the negative rotation profile has a destabilizing effect. The study shows that the modulated system conveys more heat and mass than the unmodulated system.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135496792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation the Structural Influences of Silver Oxide Addition in the Bioactive Phosphate Glasses","authors":"Ruqaya H. Hussian, Dunia K. Mahdi","doi":"10.26565/2312-4334-2023-3-32","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-32","url":null,"abstract":"This research investigates the impact of varying concentrations of silver oxide on the structure and morphology of phosphate bioactive glass (PBG). PBGs are gaining popularity as a potential replacement for traditional silicate glasses in biomedical applications due to their adjustable chemical resistance and exceptional bioactivity. Upon examination of the scanning electron microscope of the composites without Ag2O, it was observed that the grains tended to merge together, and the surface particles appeared to be larger than those in composites with Ag2O at concentrations of 0.25, 0.5, and 0.75 wt%. The study found that the diffraction pattern of phosphate bioactive glass composites sintered without Ag2O showed the presence of Strontium di-phosphate and Calcium di-phosphate. The XRD pattern of these composites without Ag2O revealed specific planes that corresponded to both types of di-phosphate. However, when Ag2O was added, a new cubic phase was detected, and the intensity of the calcium and strontium diphosphate increased with higher Ag2O content. The XRD pattern of the composites with Ag2O displayed specific planes that corresponded to Ag2O. In other words, the absence of Ag2O in the composite material led to larger particle sizes and less distinct boundaries between grains. In addition, it has been found that, as the concentration of Ag2O increased from 0 to 0.25, 0.5, and 0.75 wt%, the average crystallite size decreased from 36.2 to 31.7, 31.0, and 32.8 nm, respectively. These results suggest that the addition of Ag2O can effectively reduce the average crystallite size of the composite materials. Also, as the concentration of Ag2O increased from 0 g to 0.5 wt% within the composite material, the average lattice strain increased from 3.41·10-3 to 4.40·10-3. In simpler terms, adding Ag2O to the composite material resulted in a slight increase in the average lattice strain.
","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135496797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsteady Flow Past an Accelerated Vertical Plate with Variable Temperature in Presence of Thermal Stratification and Chemical Reaction","authors":"Nitul Kalita, Rudra Kanta Deka, Rupam Shankar Nath","doi":"10.26565/2312-4334-2023-3-49","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-49","url":null,"abstract":"This work aims to investigate the effect of thermal stratification on fluid flow past an accelerated vertical plate in the presence of first order chemical reaction. The dimensionless unsteady coupled linear governing equations are solved by Laplace transform technique for the case when the Prandtl number is unity. The important conclusions made in this study the effect of thermal stratification is compared with the scenario in which there was no stratification. The results of numerical computations for different sets of physical parameters, such as velocity, temperature, concentration, skinfriction, Nusselt number and Sherwood number are displayed graphically. It is shown that the steady state is attained more quickly when the flow is stratified.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135497843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Calcination Temperature on Structural and Optical Properties of Nickel Aluminate Nanoparticles","authors":"Katrapally Vijaya Kumar, Sara Durga Bhavani","doi":"10.26565/2312-4334-2023-3-37","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-37","url":null,"abstract":"Nickel aluminate (NiAl2O4) nanoparticles were synthesized using sol-gel method with auto-combustion. The prepared nanoparticles were made into four parts and calcinated at 700, 900, 1100 and 13000C and taken up for the present study. The taken-up nanoparticles were characterized using powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersion X-Ray Spectroscopy (EDS), Fourier Transform and Infrared (FT-IR) spectroscopy and UV-Vis spectroscopy techniques. The X-ray diffraction patterns confirmed the spinel structure and Fd3m space group. Scherrer formula was used to calculate the crystallite size and found in the range 5.78 to 20.55 nm whereas the lattice parameter was found in the range of 8.039 to 8.342 Å. The average grain size was found in the range 142.80 to 187.37 nm whereas interplanar spacing was found in the range of 2.100 to 2.479 Å. The FTIR spectroscopy showed six absorption bands in the range 400 to 3450 cm-1 and confirmed the spinel structure. The optical band gap (Eg) was decreased with calcination temperature and found in the range 4.2129-4.3115eV.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Properties of “Higher Manganese Silicide-Silicon” Heterostructure","authors":"Kobiljon K. ugli Kurbonaliev, Nurulla F. Zikrillaev, Akhmadjon Z. Khusanov","doi":"10.26565/2312-4334-2023-3-27","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-27","url":null,"abstract":"Based on the diffusion technology, many scientists and specialists have conducted research on obtaining materials that are fundamentally different in electrical and photo-thermal parameters from the original material by introducing various input atoms into semiconductor materials and creating deep energy levels in their band gap. The electrical, photoelectric, optical, and magnetic properties of these semiconductor materials have been extensively studied with metal group elements, isovalent elements, and rare earth elements added to silicon through the process of growth, ion implantation, or diffusion from the gaseous state. The technology of introducing impurity atoms into silicon by the diffusion method is distinguished from other methods in its simplicity, energy efficiency, and low cost. Up-to-date, the technology of changing the resistivity and conductivity of the initial sample by diffusion of manganese atoms into single-crystal silicon is studied insufficiently. In the article, it was determined that when manganese atoms diffuse into silicon, a high-manganese silicide is formed on its surface and in the near-surface layer. Based on the analysis of the experimental results, the thermal EMF (electromotive force) in Mn4Si7-Si -<Mn>-Mn4Si7 structures in a certain temperature range and under illumination (with monochromatic or integrated light) is explained by the fact that it based on the Pelte effect, observed in semiconductors.The volt-ampere characteristics (VAC) of the obtained structures were measured at various temperatures, in the dark and in the light. Formation of a boundary layer with high resistivity at the boundary of the higher manganese-silicon transition, the transition from higher manganese silicide to the base of the structure due to the effect of ionization of pores during illumination of structures and external influence. The applied field was clarified based on VAC results. The manganese high silicide layer formed on the silicon surface has the properties of a semiconductor, and the formation of a heterojunction upon transition to silicon is shown on the basis of the sphere diagram.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation of Responsive Elements of Planar Multi-Element Photodiodes","authors":"Mykola S. Kukurudziak","doi":"10.26565/2312-4334-2023-3-48","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-48","url":null,"abstract":"In the mass production of multi-element silicon p-i-n photodiodes, the problem of systematic rejection of products due to a decrease in the insulation resistance between the active elements of photodetectors has been revealed. The purpose of this work is to study the causes of insulation resistance degradation and to establish optimal methods for avoiding this phenomenon. A comparative analysis of three insulation methods was carried out: classical insulation by the surface of a non-conductive substrate and a dielectric layer; insulation by means of mesaprofile grooves with a dielectric film; insulation by means of areas of limitation of surface leakage channels isotypic with the substrate material (in this case, p+-type) formed in the gaps between active elements. The study found that the reason for the deterioration of the insulation resistance between the active elements of photodiodes is the presence of conductive inversion channels at the Si-SiO2 interface due to the use of silicon with high resistivity. One mechanism for the formation of inversion channels is the redistribution of impurities in the masking oxide (in particular, phosphorus) and their diffusion to the interface during thermal operations. Another mechanism for the formation of inversion layers is the diffusion of boron from silicon into SiO2 during heat treatment due to the fact that the boron segregation coefficient is less than one. In the manufacture of samples with insulation using non-conductive areas of the substrate, a decrease in insulation resistance was observed as the technological route was performed (after each subsequent operation, the resistance degraded). The degree of degradation can be reduced by reducing the duration of thermal operations. It has been shown that reducing the thickness of the masking oxide causes a decrease in insulation resistance. When using mesa-technology, it is possible to increase the insulation resistance by eliminating the high-temperature oxidation operation and, in fact, due to the absence of a masking coating during phosphorus deposition. Insulation by means of p+-type areas in the gaps between the active elements allows to obtain the highest insulation resistance values. The formation of these regions with a width of 100 μm in the gaps with a width of 200 μm allowed us to obtain an insulation resistance of 25-30 MΩ. To ensure the insulation of the active elements of photodiodes by this method, two thermal operations are added to the technological route. The number of thermal operations can be reduced by doping the entire silicon surface with a low boron concentration before forming a masking coating.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}