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Systematic Investigation of Close-Packed Silica Nanospheres Monolayer under Sintering Conditions
摘要： In this paper, we have quantified and investigated the effect of various sintering temperature on close-packed Silica Nanospheres (SNs) monolayers. SNs with diameters of 140, 175 and 220 nm were fabricated by an effective and reliable spin-coating technique. The fabricated SNs monolayers were sintered up to 1200°C and were analyzed from FESEM to investigate in details for local and extended transformations in their structural and morphological properties. A distinct "neck-formation" was observed and was quantified with different particle size distribution as well as surface packing density. It was observed that SNs monolayer undergoes intra-particle reformation in the form of shrinkage in individual SNs and compactification of growth domains, followed by inter-particle sintering. A geometrical model was developed to determine the curvature radius and interpenetration depth thus enabling us to quantify the parameters that dominate the dynamics of the sintering process for such non-porous SNs.
关键词： Scanning Electron Microscopy,Geometrical Model,Silica Nanospheres,Sintering
更新于2025-09-10 09:29:36
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Flow through polydisperse pores in an anodic alumina membrane: A new method to measure the mean pore diameter
摘要： We describe a novel technique for the characterization of the mean pore radius of self-ordered porous anodic alumina membranes. We have studied the flow of liquids through cylindrical membrane pores under conditions of very low Reynolds number (Re ? 1). We find that the flow data are well-described by Poiseuille’s law. Characterization is achieved through the application of the H?gen-Poiseuille equation on flow measurements conducted in a simple and compact experimental setup. This setup allows for the monitoring of flow as a result of the pressure difference between the two sides of the membrane without the use of sophisticated and costly laboratory equipment. The proposed method has been tested by flow experiments using liquids of various viscosities. Good agreement is found between the results obtained from the flow data and the pore radii measured by scanning electron microscopy. Consistent results for the mean pore radius for the same membrane have been obtained in all cases.
关键词： Poiseuille’s law,scanning electron microscopy,anodic alumina membrane,mean pore diameter,flow measurement
更新于2025-09-10 09:29:36
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Effects of Strategically Placed Water Droplets on Monolayer Growth of Molybdenum Disulfide
摘要： Two-dimensional (2D) molybdenum disulfide (MoS2) films with a tunable bandgap hold great promise for next-generation electronic and optoelectronic devices. Synthesis of large areas of high-quality MoS2 monolayers lacks experimental reproducibility. Moreover, the outcome of MoS2 growth by chemical vapor deposition is dependent on several interconnected growth parameters. In this study, we present results of MoS2 monolayer growth by strategically placing water droplets on the growth substrate and/or in the source prior to its loading in the growth chamber. The volume and distribution of water on the growth substrate and in the source had a direct impact on the morphology of the as-grown MoS2. Characterized by scanning electron microscopy (SEM), Raman microscopy, and atomic force microscopy (AFM), the number and size of MoS2 layers as well as its distribution on the growth substrate were found to have a strong dependence on the positioning of the water droplet. This study on MoS2 monolayer growth using water droplets as a promoter provides a simple and reproducible experimental technique enabling growth with high reliability.
关键词： molybdenum disulfide,water droplets,Raman microscopy,scanning electron microscopy,chemical vapor deposition,atomic force microscopy,monolayer growth
更新于2025-09-09 09:28:46
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STRUCTURING OF DIAMOND FILMS USING MICROSPHERE LITHOGRAPHY
摘要： In this study, the structuring of micro- and nanocrystalline diamond thin films is demonstrated. The diamond films are structured using the technique of microsphere lithography followed by reactive ion etching. Specifically, this paper presents a four-step fabrication process: diamond deposition (microwave plasma assisted chemical vapor deposition), mask preparation (by the standard Langmuir-Blodgett method), mask modification and diamond etching. A self-assembled monolayer of monodisperse polystyrene (PS) microspheres with close-packed ordering is used as the primary template. Then the PS microspheres and the diamond films are processed in capacitively coupled radiofrequency plasma using various plasma chemistries. This fabrication method illustrates the preparation of large arrays of periodic and homogeneous hillock-like structures. The surface morphology of the processed diamond films is characterized by scanning electron microscopy and with the use of an atomic force microscope. The potential applications of these diamond structures in various fields of nanotechnology are also briefly discussed.
关键词： polystyrene microspheres,nanostructuring,scanning electron microscopy,reactive ion etching,diamond thin films
更新于2025-09-09 09:28:46
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Structural, morphological and optical properties of Cu2ZnxFe1-xSnS4 thin films grown by thermal evaporation
摘要： In this study, Cu2ZnxFe1-xSnS4 (CZFTS) (0≤x≤1) thin films were grown under vacuum evaporation on unheated glass substrates followed by sulfurization at 400 °C. The effects of sulfurization on the structural, morphological and optical properties were investigated for CZFTS material by varying Fe content. Crystal structure and phase of CZFTS thin films were analyzed by X-ray diffraction technique and Raman spectroscopy. In addition, the elemental composition and the stoichiometry of films were studied using energy dispersive spectroscopy. Surface morphology of samples was examined by scanning electron microscopy. Optical properties such as absorption coefficient, and gap energies were determined by the measurement of transmittance and reflectance in the spectral range 300-1800 nm. X-ray analysis indicates that all sulfurized CZFTS films present a polycrystalline nature and exhibit a preferential orientation along (112) plane. Cu2FeSnS4 (x=0) and Cu2ZnSnS4 (x=1) crystallize in stannite structure with I-42m and kesterite structure with I-4 space group, respectively. Raman analysis and elemental composition confirm that only the Cu2ZnSnS4 (x=1) and CZ0.75F0.25TS (x=0.75) phases are present with good crystallinity. Transmittance and reflectance spectra revealed that the films are homogenous mostly for x=0.75 and 1. Structural and optical parameters like crystallite size, absorption coefficient and band gaps were estimated for all the x values.
关键词： Sulfurization,Scanning electron microscopy,X-ray diffraction,Copper zinc iron tin sulfide,Evaporation,Thin films
更新于2025-09-09 09:28:46
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Gill Morphology in Two Bottom Feeder Mediterranean Sea Fishes: Grey Gurnard Fish (Eutrigla gurnardus, Linnaeus, 1758) and Striped Red Mullet Fish (Mullus barbatus surmuletus, Linnaeus, 1758) by Scanning Electron Microscopy
摘要： The purpose of the current investigation was to describe the gill morphology of two bottom feeders Mediterranean Sea fishes: Striped red mullet fish (M. surmuletus) and grey gurnard fish (E. gurnardus) that showed the same feeding habits. The gill system of the grey gurnard consisted of four pairs of gill arches while consisted of three pairs of gill arches in the striped red mullet. Our study focused on the scanning electron microscopical (SEM) features of the gills, where some differences in the gill arches and gill rakers surface in both species were observed. Our results marked that there was an interbranchial septum carrying a four transverse elevated crest in grey gurnard while in striped red mullet carrying a median longitudinal elevated crest. There are some similar structure on the gill arch of two fishes as; no angle between a ceratobranchial part and epibranchial part and also the gill arch has a region of many longitudinal microridges demarcated the region between gill rakers and gill filaments. By SEM, in striped red mullet, the smooth surface of gill arch and gill rakers was characterized by the presence of high number of taste buds. By SEM in grey gurnard, gill raker appeared as a round short projected body with high number of curved apex spines. Furthermore, in striped red mullet, gill raker appeared as short projected body with high number of rod-like spines. Gill filaments were long at middle and short at extremities of gill arch in both species.
关键词： Grey gurnard fish,Striped red mullet fish,Gill arch,Gill filament,Gill raker,Scanning electron microscopy
更新于2025-09-09 09:28:46
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Photocatalytic Degradation of Gentian Violet with Li Doped Bismuth Oxide Nanorods
摘要： Li doped bismuth oxide nanorods have been synthesized via the hydrothermal route. The obtained nanorods possess semi-circular tips, the length and diameter are 1–5 μm and 50–350 nm, respectively. The photocatalytic activity of the Li doped bismuth oxide nanorods has been analyzed by the photocatalytic degradation of gentian violet (GV). GV with the concentration of 10 mg · mL?1 can be photodegraded totally in the presence of 10 mg Li doped bismuth oxide nanorods under UV light irradiation for 60 min. The photodegradation ratio of the Li doped bismuth oxide nanorods is closely relative to the content of the nanorods and initial GV concentration. The photodegradation ratio decreases obviously with the decrease of the content of the nanorods and increase of initial GV concentration.
关键词： Photocatalysis,Li Doped Bismuth Oxide Nanorods,Gentian Violet,Scanning Electron Microscopy
更新于2025-09-09 09:28:46
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Experimental Investigations of Phase Equilibria in Ternary Ag-Cu-Ga System
摘要： Experimental study of phase equilibria in the ternary Ag-Cu-Ga system was carried out by using DTA/DSC, isothermal equilibration and microscopic as well as x-ray analyses. DTA experiments were conducted for alloys, whose concentrations varied along two cross-sections determined by the ratio of mole fractions xAg/xCu = 1:1 and xAg/xGa = 1:1. Equilibration of samples was carried out at 200, 450 and 650 (cid:3)C. The obtained information about phases in equilibrium was compared with the results of calculations of the phase diagram for conditions identical to our experiments. It was demonstrated that the results of calculations are compatible with the experimental data.
关键词： CALPHAD method,x-ray diffraction,DTA measurements,Ag-Cu-Ga system,phase equilibria,scanning electron microscopy
更新于2025-09-09 09:28:46
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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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Synthesis and Pholuminescence studies of polymer capped SnO2 nanoparticles synthesized by chemical co-precipitation method
摘要： In recent years many research works have been focused on the electrical and optical properties of metal oxides. In this present paper SnO2 nanoparticles have been synthesized by chemical co-precipitation method using different capping agents like EDTA (ethylene diamine tetra acetic acid), PVP (polyvinylpyrrolidone), PVA (polyvinyl alcohol) and studied the influence of capping agent on various properties of SnO2 nanoparticles. Structural, surface morphology, chemical analysis and luminescence properties of prepared SnO2 nanoparticles were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) attached with energy dispersive analysis of X-rays (EDAX) and photoluminescence studies (PL). X-ray diffraction study reveals the nano-size particle distribution of the prepared samples with tetragonal rutile structure in the range of 3 to 9 nm. FTIR spectra show the structural confirmation of SnO2 nanoparticles. Various PL signals were observed in the visible region around 375 nm to 600 nm due to oxygen vacancies and interfacial Sn vacancies present in the prepared nanosamples.
关键词： X-ray diffraction,scanning electron microscopy,Nano-size distribution,Chemical co-precipitation,Photoluminescence
更新于2025-09-04 15:30:14