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Investigation on Structural and Dielectric Properties of Silica Nanoparticles Incorporated Poly(Ethylene Oxide)/Poly(Vinyl Pyrrolidone) Blend Matrix Based Nanocomposites
摘要： Inorganic and organic materials based polymer nanocomposite (PNC) films, comprising silica (SiO2) nanoparticles as inorganic filler and the polymer blend of poly(ethylene oxide) (PEO) and poly(vinyl pyrrolidone) (PVP) as organic matrix (i.e., (PEO–PVP)-x wt% SiO2; x = 0, 1, 3 and 5) have been prepared by the solution-casting method. These PNC films are characterized by employing the scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, and the dielectric relaxation spectroscopy (DRS). The effect of SiO2 nanofiller on the spherulite and porous morphology, miscibility of the polymers, PEO crystallite size, the degree of crystallinity, polymer–polymer and polymer-nanoparticle interactions, and from 20 Hz to 1 MHz range dielectric and electrical dispersion behaviour and also the structural dynamics of these PNC materials have been investigated. The porous morphology, structures of miscible phases, and the PEO crystallite length greatly alter with the incorporation of merely 1 wt% SiO2 in the polymer blend matrix which further changes with the increase of nanofiller concentration up to 5 wt%. The real part of complex permittivity over the radio frequency range (20 kHz–1 MHz) for these PNC films is found about 2 and their dielectric loss tangent values below 0.03, at the room temperature, which are significantly low. The contribution of interfacial polarization effect at lower audio frequencies enhances the complex permittivity of these materials linearly in the range 2 to 4 with the decrease of frequency from 1 kHz to 20 Hz confirming their frequency tunable dielectric behaviour. The dielectric study of 3 wt% SiO2 containing PNC film in the temperature range 30–60 °C reveals its thermally activated dielectric characteristics, and the temperature dependent values of dielectric relaxation time and dc electrical conductivity obey the Arrhenius behaviour with activation energies in the range 0.2–0.3 eV. The dielectric and electrical parameters ascertain the promising applications of these PNC films in the development of novel electroactive functional materials, and also their use as the dielectric substrate and electrical insulating polymeric nanodielectrics for the fabrication of flexible-type naturally degradable organoelectronic devices.
关键词： Electrical conductivity,FTIR,XRD,Dielectric properties,Polymer nanocomposite
更新于2025-09-09 09:28:46
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Dynamic SIMS, spectroscopic ellipsometry and x-ray diffractometry analysis of SiGe HBTs with Ge grading
摘要： In this paper, SiGe heterojunction bipolar transistors (HBTs) with Ge concentrations up to 40 atomic percent (at%) and different slopes of Ge gradients are characterized by comparing dynamic secondary ion mass spectrometry (D-SIMS) and multi-angle spectroscopic ellipsometry (SE). X-ray diffractometry (XRD) was used as reference. D-SIMS results show that sputter rate and Ge content calibration have major impact on depth pro?le measurements of HBTs with graded SiGe. Strained and relaxed SiGe show differences in Ge content calibration and no difference in sputter rate calibration. Jiang’s protocol was used for Ge content calibration and proven to be valid up to ～50 at% Ge. SE with a combination of 3 angles of incidence (AOIs) (59, 65, 71°) in comparison with the single AOI (71°) realized in industrial setup for semiconductor manufacturing environment was analyzed to ?nd a more stable solution for revealing the thickness of plateau and gradient parts of SiGe base. SE with 71° AOI and rotating compensator is the best choice for in-line HBT with Ge grading characterization. The determination of gradient shape continues to be a challenging task for SE, due to high parameter correlations and the need to use some ?xed parameters within the ?tting procedure. D-SIMS remains the favorite for graded pro?le determination. Results of D-SIMS and SE with ?xed parameters are in good agreement with XRD for HBTs with Ge grading.
关键词： SiGe,XRD,spectroscopic ellipsometry,SIMS,HBT
更新于2025-09-09 09:28:46
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Synthesis and Characterization of Erbium Oxide Nanocrystallites
摘要： The present article describes a method of the preparation of erbium oxide nanocrystallites (nano Er2O3) via thermal decomposition of a transient complex formed in situ from Er(NO3)3 · 5H2O and glycine. Decomposition of the complex occurred at about of (250 ± 10) °C. Ultra-fine light pink powder of erbium oxide nanocrystallites was obtained via this method. The resulting nanocrystallites were characterized using X-ray powder diffraction analysis, which showed the nanocrystallites having the crystallite size equal to 10 nm. Morphology of the nanocrystallites was examined by scanning and transmission electron microscopy. Electron diffraction observed in transmission electron microscopy corresponds to the results obtained from X-ray diffraction analysis. The elemental composition of the product was confirmed by EDS analysis.
关键词： Erbium Oxide,SEM,XRD,TEM,Nanocrystallites,Thermal Decomposition
更新于2025-09-04 15:30:14
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Microstructure and Electrochemical Behavior of TiO <sub/>2</sub> Nanotubes Coated on Titanium-Based Substrate Before and After Thermal Treatment
摘要： The comparative study of the structure and electrochemical properties of TiO2 layers on the surfaces of commercially pure titanium and Ti6Al4V alloy were performed. The TiO2 surface layers produced by anodization in ethylene glycol-based electrolyte solution using Power Supply MCS-3204 MANSON at 20 V or 40 V for 60 minutes were formed on the titanium substrates by simultaneous surface oxidation and controlled dissolving of oxide film due the fluorine ions. The SEM and X-ray diffraction analyses were performed to determine the properties of the anodized layers before and after heat treatment at 500 °C for 120 minutes. The as-anodized TiO2 nanotubes exhibited an amorphous structure. An anatase phase appeared in annealed nanotube layers of both Ti based substrates. The corrosion behavior in simulated physiological solution was compared for not anodized, anodized and anodized heat treated conditions of both titanium surfaces. The results of the electrochemical measurements corresponded to the microstructure and treatment condition. The porous feature of the anodizing layers on Ti6Al4V substrate led to lower corrosion resistance that increased after the heat treatment.
关键词： TiO2 Nanotubes,XRD,Titanium Alloy,Anodization,Microstructure
更新于2025-09-04 15:30:14
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Effect of Sputtering Technique and Properties of TiO2 Doped with SnO2 Thin Films
摘要： Doped oxide materials of 90% of TiO2 was doped with 10% of SnO2 that target has been deposited at a substrate temperature of 250°C for 1 hour by using DC Sputtering technique. The as synthesized target was TiO2-SnO2 was used to deposit on the glass substrates. The deposited oxide thin film was characterized for their structural, surface morphological, electrical and optical properties. X-ray diffraction is used for studying the nature and structure, scanning electron, atomic force microscopy and transmission electron microscopy are used to identify the surface morphology of the prepared films. The Van der Pauw technique is employed to measure electrical resistivity and Hall mobility of the film. Wide varieties of methods are available for measuring thin film thicknesses. Stylus profilometry will be helpful to find the thickness of the film, structural studies by X-ray, and micros structural analysis of the film.
关键词： Scanning Electron microscopy (SEM),Stylus profilometry,TiO2-SnO2,X-ray diffraction (XRD),UV-Vis-NIR spectrometer
更新于2025-09-04 15:30:14
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Molecular properties, crystal structure, Hirshfeld surface analysis and computational calculations of a new third order NLO organic crystal, 2-aminopyridinium benzilate
摘要： A third order nonlinear optically active (NLO) organic proton transfer compound was synthesized by the reaction between 2-aminopyridine and benzilic acid. Single crystals of the product, 2-aminopyridinium benzilate, (2-APB) were grown by slow evaporation technique and the structure of 2-APB was confirmed by single crystal X-ray diffraction. In the structural network, cations and anions are linked through N+-H…O- intermolecular hydrogen bonding interactions. Elemental analysis, thermal analysis, UV-Vis, FT-IR and 1H and 13C NMR spectroscopic analyses were carried out to assess the structure and chemical makeup of the 2-APB crystal. Computational studies that include optimization of molecular geometry, natural bond orbital (NBO), Mulliken atomic charge and HOMO-LUMO analyses were also performed using B3LYP method at 6-311+ G (d,p) level of theory to explore various intermolecular interactions especially hydrogen bonding. Hirshfeld surface analysis indicates that the contacts involving hydrogen such as H…H, C…H and O…H have greater influence on the molecular properties of 2-APB.
关键词： NBO analysis,Hydrogen bonding,DFT,Single crystal XRD,Hirshfeld surface analysis
更新于2025-09-04 15:30:14
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Structural and optical studies of gamma irradiated N-doped 4H-SiC
摘要： In this paper, the gamma irradiation effects on the structural and optical properties of N-doped 4H-SiC (n-4H-SiC) is presented up to a cumulative gamma radiation dose of 1500 kGy. The studies showed marginal and inconsistent variation in the - and -axis lattice constants of 4H-SiC due to the accumulation of gamma-induced defect states. The modifications in the longitudinal optical plasmon-phonon coupled (LOPC) modes, Biedermann absorption bands, Urbach energy ( ) and defect related photoluminescence (DPL) bands are discussed at different (500, 1000 and 1500 kGy) irradiation doses. Despite these effects, the overall gamma-induced disorder ( ) and variation in the free carrier concentrations ( ) are found to be negligible and demonstrating the radiation resistant property of n-4H-SiC under gamma radiation environment.
关键词： PL,Silicon carbide,XRD,LOPC modes,Gamma irradiation
更新于2025-09-04 15:30:14
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Studies on Different Doped Zn Concentrations of CdSe Thin Films
摘要： Different Zn concentration was doped with CdSe thin films by Electron Beam Evaporation method. Crystallite variation was studied for doping effect and it was found to be about 40 to 50 nm respectively. Optical band gap values are found to be modified by doping as well as annealing. Annealed films showed considerable influence in their opto-elctronic and structural properties, which provided improvement in conversion efficiency of about 2.75% and 2.87% respectively.
关键词： PEC solar cells,Electron beam evaporation,Doping effect,XRD of CdSe
更新于2025-09-04 15:30:14
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Synthesis, Growth and Structural Characterization of Semi Organic Non-Linear Optical Material: L-Arginine Doped Zinc Sulphate Heptahydrate Single Crystal
摘要： A method of slow evaporation was adopted to grow pure semiorganic non linear L-arginine doped zinc sulphate heptahydrate single crystals. The lattice parameters of the grown crystals were found out using powder XRD pattern. The different functional bond frequencies linked within the crystals were analyzed by FT-IR spectroscopic analysis. The absorption spectrum (UV-visible) between 200-1100 nm illustrates the absorption in this range along with the absence of any combination modes above 270 nm. Further TG/DTA curves ensure the absence of lattice water and thermal stability of the grown crystals. The L-Arginine was added in 0.01, 0.03, 0.05 mole % to zinc sulphate heptahydrate and the compound salts were subjected to Kurtz powder technique technique. It was observed that the second harmonic generation efficiency of 0.03 mole % L-arginine doped zinc sulphate heptahydrate single crystal is very much higher than pure zinc sulphate heptahydrate. The Vickers's micro hardness measurements proved the mechanical stability of the grown crystals.
关键词： Thermal analytical technique,Non-linear optical,L-Arginine,Zinc sulphate heptahydrate,XRD
更新于2025-09-04 15:30:14
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Effect of Annealing on the Surface Morphology, Optical and and Structural Properties of Nanodimensional Tungsten Oxide Prepared by Coprecipitation Technique
摘要： Tungsten oxide (WO3) nanoparticles with monoclinic structure have been synthesized by using an inexpensive coprecipitation process. The obtained nanoparticles were annealed at 400°C, 500°C, 600°C, 700°C, 800°C, and 900°C for 1 h under the same physical conditions. The morphology, structure, and optical properties of the synthesized nanoparticles were studied by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible (UV–Vis) spectrophotometry, and Raman spectroscopy. The XRD results confirmed that the synthesized nanomaterial was crystalline in nature with monoclinic phase. The crystallite size varied from 14 nm to 87 nm when changing the annealing temperature. Williamson–Hall analysis was used to investigate the change in lattice strain and crystallite size. The optical performance was investigated by using UV–visible spectroscopy. The bandgap of the prepared nanomaterials varied from 2.51 eV to 3.77 eV with the annealing temperature, due to the variation of the effect of oxygen vacancies on the electronic band structure. SEM revealed formation of uniform and irregular-sized nanoparticles. HRTEM analysis revealed that the nanoparticles grew along the [002] plane with d-spacing of 0.39 nm for the material annealed at 500°C and along the [200] plane with spacing of 0.36 nm when annealed at 800°C. The crystalline nature of the synthesized nanomaterial was confirmed by uniform and clear fringes obtained in TEM micrographs. The correlation between the peak position and width of the key band at 806 cm?1 in Raman spectroscopy band is discussed. These enhancements in the properties of WO3 nanomaterial make it an efficient material for many potential applications, e.g., in photocatalysis, electro- and photochromic devices, etc.
关键词： HRTEM,XRD,SEM,UV–Vis spectroscopy,Raman spectroscopy
更新于2025-09-04 15:30:14