The Iraqi Journal of Applied Physics (IJAP) is a double-blind peer-reviewed journal of high quality devoted to publishing original research papers from applied physics and their broad range of applications. IJAP publishes quality original research papers, comprehensive review articles, survey articles, book reviews, and dissertation abstracts in physics and its applications in the broadest sense. It is intended that the journal may act as an interdisciplinary forum for Physics and its applications. Innovative applications and materials that bring together diverse areas of Physics are particularly welcome. Review articles in selected areas are published from time to time. It aims to disseminate knowledge; provide a learned reference in the field; and establish communication channels between academic and research experts, policymakers, and executives in industry, commerce, and investment institutions.
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Effect of Argon:Oxygen Gas Mixing Ratio on Characteristics of Silicon Dioxide Nanoparticles Synthesized by DC Reactive Sputtering
In this work, nanostructured SiO2 thin films were deposited on glass substrates using DC reactive magnetron sputtering technique. Gas mixtures of argon and oxygen at different mixing ratios were used to synthesize SiO2 nanoparticles. A transition from amorphous to partially crystalline phases was revealed as the oxygen ratio increased, indicating enhanced crystallinity under oxygen-rich conditions. The morphology of the film surface varied and the particle size decreased with higher oxygen content, suggesting improved oxidation and limited grain growth. The results confirm that the Ar:O2 gas ratio plays a critical role in tuning the structural and optical properties of SiO2 nanostructured thin films.
Copyright (c) 2025 Iraqi Journal of Applied Physics
AP0871 Structural and Electrical Properties of Bi2Te3:Al Films Prepared by Thermal Evaporation
In order to assess the influence of Al doping on the structural and electrical properties of Bi2Te3, before and after annealing, a range of tests were carried out on samples prepared through thermal evaporation. These tests included x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), Hall effect, electrical resistivity, and electrical conductivity. The XRD analysis confirmed the formation of the films, and both SEM and AFM determined that there were no defects in the fabricated films. The addition of Al resulted in a rise in carrier concentration and electrical conductivity, as well as a reduction in electrical resistivity.
AP0862 Tunable Structural and Optical Properties of Hydrothermally Synthesized Zn1-xMnxFe2O4 Nanostructures
In this study, zinc-manganese ferrite (Zn1-xMnxFe2O4) nanostructures were prepared at different Mn substitution ratios (x = 0, 0.2, 0.4) with a hydrothermal route. The structural, morphology, and optical properties of the prepared samples were studied. Results confirmed the polycrystalline nature and spinel-ferrite structure, and the crystallinity and crystallite size decreased with increasing Mn content. Spherical nanoparticles were formed with distinct levels of aggregation and porosity, relying on the Mn substitution ratio. The functional absorption bands of metallic-oxygen bonds and different molecular interactions were confirmed. A significant change in the absorption spectrum with increasing manganese content as well as an increase in the optical energy gap were osberved, indicating tunable electronic properties. The tunable structural, optical, and morphological properties of the Zn1-xMnxFe2O4 nanostructures with different Mn contents indicate their potential application in magnetic materials, catalysis, and biomedical fields.
AP0859 Structural and Mechanical Properties of Porcelain Prepared from Iraqi Raw Materials with Non-plastic Clay Additives
Porcelain is one of the most important technical ceramics, but the shrinkage in dimensions after firing resulting from plastic clays is one of the shortcomings that manufacturers suffer from. Therefore, this work aims to reduce shrinkage by adding non-plastic powder (fired kaolin (Grog): prepared by firing plastic clay up to 1100°C) and extend their effect on some other properties of porcelain. The composition of hard porcelain is: 60 wt.% kaolin, 20 wt.% flint and 20 wt.% potash feldspar as Iraqi raw materials. Non-plastic clay was added to the porcelain by 25, 30, 35 and 40 wt.% instead of kaolin. Forming the samples by axial pressing into discs then fired at 1300°C. FE-SEM images showed the emergence and increasing of the mullite phase as a result of the porcelain firing with the addition of fired clays. XRD analysis confirmed the presents of mullite phase in addition to the cristobalite phase. Increasing the non-plastic clay from 25 to 40 wt.% led to a significant decrease in linear shrinkage from 12.6 to 5.4%, increased the porosity from 12.2 to 15.1%, decreased the bulk density from 2.25 to 2.16 g/cm3, this clearly affected the decrease in the diametral strength from 23.26 to 10.48 MPa. The results obtained determined the possible application range for construction, to include thermal insulation, wall tiles and decoration.
AP0861 Nanocellulose-Based Biofuel Production from Sugarcane Bagasse: A Sustainable Approach
Sustainable biofuel production has many advantages, including that it accelerates the worldwide transition away from fossil fuels and toward renewable forms of energy. The current study included the synthesis and characterization of nanocellulose (NC) from sugarcane bagasse. The prepared NC was used to produce biofuel using a simple and rapid method including fermentation cellulose and NC using the Saccharomyces cerevisiae yeast. Gas chromatography was used to determine the concentration of produced ethanol. About 49% and 79.5% ethanol were obtained when fermentation cellulose and NC, respectively. To increase concentration of produced ethanol, calcium oxide nanoparticles (CaONPs) were prepared from egg shells and added during the distillation of ethanol. The concentration of ethanol was increased to %97 after added CaONPs due to the fact that CaONPs works as adsorbent water molecules.
AP0845 Effect of Tapered Length on Operation of Traveling-Wave Semiconductor Laser Amplifier: A Numerical Study
This article presents a simulation study on the effect of varying tapered buried ridge stripes of the active region length on the performance of InP–InGaAsP semiconductor laser amplifier (SLA). The gain bandwidth, noise figure, amplified spontaneous emission, and output noise power are analyzed using a numerical wideband steady-state model for tapered lengths ranging from 25µm to150 µm. The model involves a set of traveling-wave equations that define signal fields and photon rates with the rate equation. The results show at 3-dB point, SLA revealed a wide signal wavelength range with a gain up to 26.7 dB for an active region tapered length of 50 µm. Moreover, the gain of the SLA exhibited the lowest value at a current of 120 mA with a low noise of 2.3 dB when the tapered length was 25µm. Finally, the results showed that the noise power is inversely related to the tapered length, whereas it increases with the bias current.
AP0761 Optical and Spectral Properties of Aqueous Magnesium Chloride Solution: An Experimental Study
This spectroscopic study presents absorption and fluorescence spectra of MgCl2 to provide valuable insights into the electronic structure, energy levels, and interaction of 10-3 M MgCl2 solution with light as an absorption peak was recorded at 255 nm. The MgCl2 solution can be commonly used for dust control, ice control and road stabilization. In addition, it has a wide range of applications such as serving as a fertilizer, a mineral supplement for animals, a wastewater treatment agent, a component of artificial seawater, and a material for textiles, paper and cement. It can also be found in many pharmaceutical, topical or skin-related applications, and the understanding of its absorption for UV radiation could contribute to the development of UV-blocking materials or environmental sensors in the future.
AP0814 Synthesis and Characterization of Zinc Cobalt Ferrite Embedded into PAN Nanofibers for Humidity Sensing Applications
In this work, composite materials were prepared by mixing different concentrations of ferrites with polyacrylonitrile (PAN) polymer. Using the electrospinning technique, these composites were deposited on a p-type silicon wafer. The prepared samples demonstrated nanofibers in both pure PAN polymers and their composites with ferrite. Prior to examining the humidity sensing effectiveness with a percentage of relative humidity at a frequency of 10 kHz, based on ambient temperature and a relative humidity range of 50–100%, the composite nanofibers demonstrated stronger humidity sensing compared to the pure PAN nanofibers, which demonstrated a powerful resistance response. More precisely, the PAN@ferrite nanocomposite showed a broad adsorption/desorption hysteresis loop.
AP0249 Heat Conduction in Two-Phase Heterogeneous Materials: Analytical Study
The method of the calculation of the heat conduction of the two-phase heterogeneous materials, where the filler’s participles of the cubic form by the at random fashion distributed in the matrix’s volume is considered. The given method of the effective heat conduction of the heterogeneous materials is based on the probability principles of the analysis of their structure. Such approach allows not only predict the average magnitudes of the heat conduction of the binary or many-component compositions but also to determine the bounds where their measured valuations will be realized with the given of the degree of certainty. The received formulas are applied in a wide range volume correlation changes and heat conduction of the separated components and also typical sizes of the researched samples.
Optimization of Si/SiGe HBT Architecture Integrated in 28-nm FD-SOI BiCMOS Technology
This work aims to investigate a new Si/SiGe HBT in the fully depleted silicon on insulator technology (FD-SOI 28 nm). The epitaxial extrinsic base isolated from the collector (EXBIC) architecture has been used in this technology to reduce base resistance and enable cut-off frequencies to exceed 400 and 600 GHz for transition frequency ft and maximum oscillation frequency fmax, respectively. Static and dynamic characteristics of the FD-SOI 28 nm have been evaluated using COMSOL multiphysics software. The technology achieved at base-emitter voltage of 0.83V, a value of 346 and 763.35 GHz for ft and fmax, respectively. To further enhance frequency performance, architecture parameters such as germanium concentration, extrinsic base doping, emitter height and width are optimized achieving ft of 360 GHz and fmax of 900 GHz. The results demonstrate the potential of using the SiGe HBTs based on the FD-SOI technology in the RF modules and THz systems.
Effects of Destroying Iran Nuclear Reactors on Human Health and Environment in Iraq: A Fast Review
No breaking news could be more critical than the destruction of three nuclear facilities in a neighboring country. As well, no news travels faster than the radiation and hazardous materials from such an event reaching your city. On the morning of Sunday, June 22, 2025, following major U.S. Air Force strikes on Iran's Fordow, Natanz, and Isfahan nuclear sites, the most pressing concern for Iraqis is undoubtedly the immediate and long-term consequences for their lives, environment, and children's future. This review outlines the most crucial aspects concerning human health and the environment, along with the necessary safety and preventive measures to minimize the risks associated with such an event, especially for Iraq, which is highly susceptible to the negative impacts of these strikes.
Nuclear reaction; Radioactive pollution; Radiation protection, Safety
AP01006 Preparation of Silver Nanoparticles from Lemon Juice Extract by Eco-friendly Chemical Reduction Method
The present work tries to investigate the possibility of preparing eco-friendly silver nanoparticles through the reduction process of Touilodin Blue Dye and lemon juice extract. XRD analysis indicates a face-centered cubic crystalline structure of the nanoparticles. In UV-visible spectroscopy, a distinct plasmon resonance band within 400-500 nm confirmed nano-sized silver particle formation. FE-SEM analysis supported a uniform particle size distribution and semi-spherical shape for the nanoparticles. The results show that the use of TB dye and lemon juice makes the process of synthesis not only eco-friendlier but also increases biocompatibility and applicability of the nanoparticles in photothermal treatments and environmental remediation; hence, this study advances green nanotechnology, illustrating that natural plant extracts can efficiently be utilized for the production of nanoparticles in an environmentally friendly approach.
AP01015 Extracting the Free Volume and Hole Fraction of Based Polymers under Positron Annihilation Lifetime Spectroscopy Technique
In this study, the polymer structures of PMMA, SAN and SMA polymers were examined from bulk to surface by positron energy. The polymers were analyzed by Positron Annihilation Lifetime Spectroscopy (PALS), the latest technique for studying the structure of polymers. The most important parameters of PALS technique are orthopositronium lifetime τ3 (o-Ps) and orthopositronium intensity I3 (o-Ps), These parameters help us to measuring the free volumes and hole fraction of the polymers, these physical parameters play important role in innovation new polymers. The free volume and holebility ratio measured with the PALS technique as a function of electronic density. The minimum and maximum values of free volume were determined in PMMA and SAN, the minimum and maximum values of holebility ratio were determined in SMA and PMMA respectively.
AP01058 Graphene Reinforced BFO: New Nanocomposite for Multifunctional Applications for Future Technology
This research illustrated the effective synthesis of graphene (0.04 mol) reinforced BFO composite and assessed its spectroscopic properties for various important applications, including supercapacitors and photocatalytic activities. The Raman analysis revealed the presence of D, G, and 2D peaks in the graphene. The energy band gap was measured to be an impressive 1.61 eV. Functional groups associated with the graphene were identified through Fourier-transform infrared (FTIR) analysis. These characteristics, along with the results from transmission electron microscope (TEM) microstructural analysis, confirm the high quality of the few-layer (2-4) graphene. Graphene reinforcement significantly increases the BET surface area of BFO from 4.2 to 78 m2/g. Remarkably, it also reduces the energy band gap of BFO from 2.62 to 1.68 eV upon adding graphene. The electrical conductivity of BFO has been evaluated at 4.2x10-4 S/cm. However, the conductivity value is projected to increase to 2.58 S/cm for our BFO/graphene (4 mol) composite.
Effect of Oxygen Gas Plasma Jet on Reactive Oxygen Nitrogen Species Dissolved in Sodium Chloride and Glucose Solutions
This study investigates the generation and stability of reactive oxygen and nitrogen species (RONS) in medical-grade sodium chloride and glucose infusion solutions following treatment with a non-thermal oxygen gas plasma jet. The plasma system operated at 10 kV and 30 W with an oxygen flow rate of 2.5 L/min and treatment durations of 5, 10, 15, and 20 minutes were applied. Optical emission spectroscopy (OES) confirmed the presence of oxygen and entrained nitrogen species in the plasma discharge. while the concentrations of NO₂⁻, NO₃⁻, and H₂O₂, as well as pH and temperature, Chemical analyses showed that nitrite (NO₂⁻) peaked at 1 ppm after 5 minutes of exposure but became undetectable in contrast nitrate (NO₃⁻) concentrations increased and stabilized at 100 ppm, while hydrogen peroxide (H₂O₂) levels rose progressively to 100 ppm by 20 minutes. A notable pH reduction was observed, decreasing from 4.5 in untreated samples to 1.8 after 20 minutes of plasma exposure, indicating pronounced acidification. Storage stability tests conducted over 50 hours revealed that H₂O₂ degraded over time, while NO₃⁻ remained relatively stable. These findings demonstrate the potential of oxygen plasma jets for the chemical activation of physiologically relevant solutions, highlighting their applicability in sterilization, wound care, and disinfection.
Enhancement of Optoelectronic Properties of Electrospun PVA Fibers by Adding Zinc and Cobalt Ions for Photodetection Applications
In this work, polyvinyl alcohol (PVA) nanofibers dual mixed with zinc (Zn) and cobalt (Co) ions were prepared using an electrospinning technique with a precursor solution consisting of, citric acid, and zinc acetate. A polycrystalline structure was revealed for all samples, with peaks corresponding to the semi crystalline-PVA. The branched fibers of mean diameters increased with increasing Co ratio were shown. When the cobalt concentration was increased, the direct bandgap energy decreased from 3.2 to 2.3 eV. A conversion from p- to n-type conductivity was proved with increasing Co ratio. An increase in photoconductivity was observed in the prepared films with increasing Co ratio. The fabricated photodetector demonstrated excellent stability and reproducibility with a notable sensitivity of 503.8% under 380 nm illumination wavelength with a power density of 5.02 mW/cm2 for the sample prepared at Co:Zn atomic ratio of 4:6.
ZnO Nanorods Synthesized by Hydrothermal Method Doped with Nanomaterials (Au, Cu, Pt, Ni, and Gr): Structural Properties Comparative Study
In this research, ZnO nanorods were prepared successfully using the hydrothermal method. Pure ZnO was doped with many nanoparticles (Au, Cu, Pt, Ni, and Gr), and the effect of these dopants on the structural and morphological properties was examined. X‑ray diffraction (XRD) showed the formation of a hexagonal wurtzite structure crystal in all Pure and doped samples with an average particle size of ~11nm and some weak peaks of dopant crystalline nanoparticles. The surface morphology of undoped and doped ZnO with nanoparticles was investigated using scanning electron microscopy (SEM), and it was observed to be a nanorod. Atomic force microscopy (AFM) images have shown that surface and morphology roughness were influenced by doping. FTIR spectroscopy has been used to investigate the functional groups in forming pure and doped ZnO.
AP01050 Highly-Pure Silicon Nitride Nanomaterial Prepared by Chemical Nitridation Method
In this work, highly-pure silicon nitride nanopowders were prepared by chemical nitridation method. The tetraethyl orthosilicate (TEOS) was used as a precursor for silicon alkoxide while ammonia was used as a precursor for nitrogen. The structural characteristics of the prepared nanopowders were determined and studied as functions of annealing temperature carried out during the preparation method. The chemical method used in this work can be characterized by low cost, simple requirements, and reliability to produce highly-pure nanopowders. Results showed that the prepared nanopowders largely maintain an amorphous or highly nanocrystalline structure, even at 1100 °C. Significant crystallization into well-defined crystalline phases of Si3N4 does not occur under these annealing conditions. While the material remains nanostructured, annealing at higher temperatures (especially 1100 °C) leads to some degree of particle growth or rearrangement, even without full crystallization. The silicon (Si) and nitrogen (N) peak intensities remain largely consistent, indicating that the stoichiometry of Si3N4 is maintained. A small carbon is residual from the chemical nitridation process or atmospheric contamination. This impurity appears to be stable or present consistently across the different annealing temperatures. The chemical nitridation method, combined with annealing up to 1100 °C, primarily yields amorphous or highly nanocrystalline Si3N4 nanopowders. While higher temperatures promote some particle growth, they do not induce significant crystallization, and the overall elemental composition remains consistent with a minor carbon impurity.
Enhancing P3HT-Based Organic Solar Cells via CsGeI₂Br Perovskite Interlayer Integration
In this study, the impact of incorporating an intrinsic perovskite layer (CsGeI₂Br) on the performance of P3HT-based organic solar cells was investigated using numerical simulation. A multi-layer device structure (PCBM/C60/P3HT/Cu₂O) was modeled with and without the insertion of the perovskite layer between the C60 and P3HT layers. Various physical parameters were optimized, including the perovskite thickness, bandgap, electron affinity, defect density, and effective density of states. The results indicate that the inclusion of the perovskite layer enhances photon absorption, facilitates charge carrier separation, and reduces recombination losses-resulting in a significant improvement in power conversion efficiency (PCE). The optimized structure achieved a PCE of 33.46%, compared to 26.9% for the device without the perovskite layer. These findings highlight the potential of lead-free perovskite materials in advancing high-performance, environmentally sustainable organic photovoltaics.
Characterization of Aluminum-Doped Titanium Dioxide Thin Films Prepared by Pulsed-Laser Deposition
In this research , thin films of pure titanium oxide doped with aluminum ratios of (2,4)% have annealed after they have deposited on glass substrates , using the pulsed laser deposition method . tests showed the appearance of clear peak for titanium oxide (103) corresponding to the angle 2Ɵ=(36.91o). The crystalline structure of the TiO₂ films is Monoclinic . The results of the atomic force microscope showed a degradation in the grain size of pure and doped films as a responsibility for annealing, which led to an dgradatione in the surface roughness. SEM images also showed of pure titanium dioxide films inlaid with (Al). It revealed a very homogeneous distribution of atoms with agglomeration to appear as clusters of scattered grains that resemble clusters of grapes in structure. Also the energy gap has decreased in its values from 3.47eV- to 3.36eV.
Impact of i-Layer Thickness on Band Alignments of a-Si:H Solar Cells: A Simulation Study Using SCAPS Software
Energy band alignments regarding amorphous silicon solar cells are assessed using SCAPS-1D software both under illumination and in dark. We looked at how the thickness of the extrinsic and intrinsic layers affected the band bending as well as alignment of the energy bands, as well as how they affected solar cell performance. Several thicknesses of the intrinsic layer are used, starting from 10nm to 60nm, while the extrinsic layer's thickness stays fixed and symmetric in all devices (20nm, 30nm, 40nm, 50nm, 60nm, 70nm, and 80nm). The findings show promise for determining the PIN thickness for amorphous silicon-based flexible solar cells. Higher thicknesses are also used, and comparisons are introduced based on the band bending, Fermi level position, splitting, and depletion region width observed. The band bending has shown different behavior based on different PIN thicknesses. Solar cell results show independent behavior on the PIN thickness and the depletion region width. The device with a thickness of 180 nm (i = 80 nm, N = 50 nm, and P = 50 nm) and a JSC of 14.4mA/cm2, open circuit voltage of 1.03 volts, an FF of 77.1%, and a PCE of 11.4% is shown to have the best performance. The performance of thicker PIN solar cells is obviously decreased
Electrical and Structural Properties of LiNi0.5Fe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Technique under Different Calcination Temperatures
Lithium nitrate, nickel nitrate, and ferric nitrate are utilized as precursors, with citric acid acting as a chelating agent. Li-Ni ferrite nanoparticles (LiNi0.5Fe₂O₄) were manufactured via the sol-gel auto-combustion method. The synthesis technique was followed by calcination at temperatures of 400°C, 600°C, and 800°C. The impact of calcination temperatures on the crystalline structure, surface morphology, and dielectric properties of LiNi₀.₅Fe₂O₄ nanoparticles was methodically examined. XRD examination verified the existence of a single-phase cubic spinel structure. The crystallite size was ascertained from the dominant peak (311). An augmentation in crystallite size was noted with elevated calcination temperatures (i.e., from as-burnt to 800°C), varying from 28.314 nm to 40.940 nm. The lattice constant attained its maximum value of 8.292 Å at 400°C, which suggests structural relaxation (i.e., partial cation redistribution) during early-stage crystallization. FTIR spectra exhibited three unique absorption bands indicative of the nanoparticles' chemical nature. Moreover, electrical experiments revealed that both the dielectric constant and dielectric loss diminished with rising frequency at the calcination temperature of 800°C. For instance, ε' decreased from 30 ± 0.5 (100 Hz) to 0.2 ± 0.05 (1 MHz), while tanδ reduced from 4 ± 0.1 to 1.5 ± 0.05 over the same range.
Synthesis of Silver Nanoparticles via Pulsed Laser Ablation in Liquid and Their Antibacterial Evaluation
Silver nanoparticles were prepared by pulsed laser ablation. Their physical and chemical properties were studied utilizing various techniques, including structural and morphological analysis. The silver nanoparticles exhibited a distinct absorption peak at approximately 425 nm in ultraviolet-visible (UV-Vis) spectroscopy, confirming particle formation. The optical band gap was estimated to be approximately 2.3 eV, indicating distinct electronic properties. X-ray diffraction (XRD) analysis revealed a crystalline phase of the silver nanoparticles. Field-emission scanning electron microscopy (FESEM) images revealed spherical particles with an average size ranging from 10 to 50 nm. FTIR spectroscopy revealed changes in the chemical bonds and surface functionalities of the particles. The particles demonstrated antimicrobial activity against E. coli (Gram-negative) and Staphylococcus aureus (Gram-positive), with higher efficacy against Gram-negative bacteria.
Green Synthesis and Characterization of Bismuth Oxide Nanoparticles for Optoelectronic Applications
The green synthesis of bismuth oxide nanoparticles (Bi₂O₃) using peppermint (Mentha pulegium) extract offers an eco-friendly, cost-effective, and scalable alternative to conventional methods. In this study, Bi₂O₃ nanoparticles were successfully synthesized and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) spectroscopy. XRD analysis confirmed a polycrystalline tetragonal structure (β-phase) with an average crystallite size of 58.06 nm, while SEM revealed uniformly distributed nanogranular-like morphologies. Optical studies demonstrated strong UV absorption (320–400 nm) and high visible-light transmittance, with a direct bandgap of 2.4 eV. Notably, the extinction coefficient (K) exhibited a pronounced peak (~1500 a.u.) at 400–450 nm, while the refractive index (n) displayed normal dispersion behavior, decreasing sharply in the visible range before stabilizing in the near-IR region. These optoelectronic properties, classified the material as a semiconductor, highlight the nanoparticles' potential for UV shielding, solar cells, photocatalysis, and optoelectronic devices. The study underscores the efficacy of plant-mediated synthesis for producing functional nanomaterials with reproducible and tunable properties, aligning with sustainable development goals.
Effect of Annealing on Optical and Electrical Properties of ZnO Film Deposited by Thermal Spraying Technique
Zinc oxide (ZnO) thin films were effectively formed onto glass substrates via the flame spray method. The ZnO films were subsequently annealed at various temperatures (350°C, 400°C, 450°C, and 500°C). The structure and optical characteristics of the ZnO films were studied by scanning electron microscope (SEM) and X-ray diffractometry (XRD) techniques. The optical properties of the films were characterized by UV-vis spectroscopy and the photoluminescence (PL) technique. Optical conductivity and optical transmittance increase with an increase in the annealing temperature. Photoluminescence (PL) analysis exhibited a significant enhancement in UV emission and a reduction in visible defect-related emissions at higher annealing temperatures, particularly at 500°C. Electrical resistivity decreases with an increase in annealing temperature. The annealing temperature is crucial in tuning the optoelectronic properties of ZnO films, with 500°C identified as the optimal temperature for achieving high optical conductivity, making these films well-suited for optoelectronic and sensing applications.
Z-Scan Characterization of Hybrid Alq₃–Gold Nanostructures for Enhanced Nonlinear Optics
In this study, the linear and nonlinear optical properties of gold nanoparticles (AuNPs) and their nanocomposites with tris(8-hydroxyquinoline)aluminum (Alq₃) were examined . The AuNPs were synthesized using pulsed laser ablation in chloroform. XRD results confirmed that the nanoparticles had a face-centered cubic structure, with an average particle size around 7 nm. The UV–Vis spectrum showed a clear peak at 340 nm, indicating the surface plasmon resonance of AuNPs, with a blue shift observed upon the addition of Alq₃, indicating strong interaction within the nanocomposite. Alq₃:AuNPs nanocomposites were prepared in three volume ratios: 2:1, 2:2, and 1:2. Nonlinear optical measurements were performed using the Z-scan technique, which showed that the samples had negative nonlinear refractive indices around 10⁻¹¹ m²/W, consistent with self-defocusing effects. Among the tested samples, pure Alq₃ showed the highest third-order nonlinear behavior. However, the Alq₃:AuNPs (2:1) nanocomposite exhibited a clear improvement when compared to the response of pure AuNPs, suggesting that adding Alq₃ enhances the nonlinear behavior of AuNPs through a synergistic effect.
Effect of Graphene Doping on structural and Electrical Properties of PAN/PPY Nanocomposites
Through chemically polymerizing pyrrole on PAN matrix with FeCl3 as an oxidant, conducting percentage ratios of PPY and PPY have been synthesized. Three distinct percentage changes are made to the (PAN/PPY) ratio: 90/10, 85/15, and 80/20. Through using the polymer approach, the synthesized nano composites are characterized. PAN/PPY nano composites with doped and undoped graphene have been studied for their electrical conductivity. The frequency dependent AC conductivity indicates that fluctuation in the conductivity regarding the nano composites is caused by both graphene doping and the concentration of PPY. It has been discovered that the PPy concentration and Gr doping decreased the nanocomposites' impedance. The results shown that the interfacial space charge (Maxwell Wagner) polarization is responsible for frequency-dependent dielectric constant for various composites at room temperature. Graphene doping is mainly an electronic lever: it tunes carrier density, mobility and inter-flake contact resistance. PPy concentration is mainly a structural lever: it determines whether a continuous conductive polymer network spans the insulating PAN matrix.Thus in PAN/PPy/graphene composite, the two levers co-operate rather than compete—doped graphene provides fast paths, PPy builds the bridges, and PAN supplies mechanical integrity. The change of dielectric loss as PPY percentage function is provided and analyzed. Frequency dependent dielectric loss is presented.
AP01038 Ag2Se Nanoparticles Synthesis by Co-Precipitation Method: Characterization and Antimicrobial Evaluation
Silver selenide (Ag2Se) nanoparticles possess promising optoelectronic properties, making them attractive for applications in biomedical fields such as bioimaging and biosensing. In this study, Ag2Se NPs were successfully synthesized via the chemical co-precipitation method. Field emission scanning electron microscopy (FE-SEM) images revealed that the nanoparticles exhibited a tightly packed lamellar-like morphology with particle sizes 48nm. X-ray diffraction (XRD) analysis confirmed the formation of an orthorhombic β-phase structure of Ag2Se. Energy-dispersive X-ray spectroscopy (EDX) confirmed the elemental composition, showing an atomic ratio of Ag to Se close to the ideal 2:1 stoichiometry. UV–visible spectroscopy showed a distinct absorption peak at 250 nm. The optical dispersion behavior was analyzed using the Wemple–DiDomenico single effective oscillator model, through which the refractive index dispersion, average oscillator energy (Eₒ), and dispersion energy (Ed) were determined. Additionally, the first-order (M-1) and third-order (M-3) spectral moments were calculated based on the extracted Eₒ and Ed values to further interpret the optical transitions. Beyond structural and optical characterization, the antibacterial activity of the synthesized Ag2Se NPs was also evaluated. The results demonstrated notable antibacterial efficacy, indicating the potential of Ag₂Se nanomaterials for applications in medical, and environmental.
Optical Properties of Polyvinyl pyridine Fibers (PVP) Prepared by Electrospinning
In this study, polyvinylpyrrolidone (PVP) nanofibers were synthesized using the electrospinning technique. The findings indicate that key process parameters, including applied voltage, polymer concentration, collecting distance, drum rotation speed, and flow rate, significantly influence fiber formation. These parameters played a crucial role in minimizing fiber diameter. This experimental investigation provides a comprehensive analysis of the impact of various electrospinning conditions on the fabrication of PVP nanofibers, contributing to a deeper understanding of the optimization of fiber morphology and properties. The structural and morphological characteristics of the PVP nanofibers were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Beyond examining fiber diameter, this research investigates how variations in electrospinning parameters influence the structural, thermal, and optical properties of PVP nanofibers The optical properties of the PVP nanofiber thin films were examined through transmission and absorption spectra measured at room temperature over the wavelength range of 300–900 nm. The optical energy gap ((Eₒ = 3.98 eV)) and other related parameters were determined using Tauc’s relation.
AP01037 Investigation of Positive Ion Motion in Ar-N2 RF Plasma Using a Cylindrical Langmuir Probe
This study presents a comparison of the Orbital Motion Limited (OML) and Allen-Boyd-Reynolds (ABR) models for describing positive ions behavior in low-temperature RF magnetron (Ar-N2) plasma containing 70%, 60%, and 50% Ar in generated using 20W RF magnetron sputtering. Analysis performed on the I-V characteristics (0 to -40 V) obtained from a cylindrical Langmuir probe employed four criteria: a comparison of experimental and theoretical ion saturation current, the Sonin plot analysis, I2-V the linearity in the ion saturation region, and the Pilling-Carnegie criterion (d(log10V)/d(log10I)) versus V- Vplasma. The ABR model accurately predicted the experimental results for the first and second criteria. The OML model agreed with the third and fourth criteria. Although this agreement was limited for the fourth criterion at β=0.16, the third criterion revealed increased linearity of the I2-V curve of Ar-N2 plasma with 70%, 60% Ar, indicating better agreement with the OML model in the saturation region than the 50% Ar plasma. Fourth criterion (the Pilling-Carnegie) indicates good agreement with the OML model for β=0.08 and 0.1, but deviation occurs at β=0.16.