Field Effect Scanning Electron Microscopy Research Articles

Microwave heat treatment on kyanite for mullite formation and the preparation of zirconia toughened mullite

This article deals with the investigations on mullite ceramics formation from Kyanite sample- an alumino-silicate mineral with microwave heating. In the present investigation kyanite was heated in microwave sintering furnace with calcined alumina, silicon carbide, zirconium dioxide and binder for mullite formation as well as for the preparation of zirconia toughened mullite product. The results of these studies reveal that how a small amount of zirconium dioxide helps in toughening the mullite formation for refractory and ceramics applications. The results shows that microwave heating method is one of the most novel and eco-friendly process for such toughened mullite formation, well within very short period of time. The observations with mullite formation and zirconia toughened mullite formation were observed with the structural data using X-ray diffraction data, field effect scanning electron microscope and energy dispersive spectroscopy. Future studies are still in process.

Investigation on Spinel Co3O4 Nanoparticles through Mechanochemical Technique

The spinel type Cobalt Oxide (Co3O4) nanoparticles were synthesized through simple mechanochemical method. The synthesized nanoparticles were characterized through X-Ray Diffraction (XRD), Field Effect Scanning Electron Microscope (FE-SEM), Energy Dispersive spectroscopy (EDS) and Raman spectroscopy respectively. The Crystallite structure of the prepared sample was analyzed through X-Ray diffractograms. The surface morphology and the presence of elements were investigated through energy dispersive spectrum. Raman spectroscopy was utilized for recording the vibrational pattern of the sample. The cyclic voltammetry and electrochemical impedance spectroscopy reveals the good electrochemical performance of the Co3O4 nanomaterials.

Structural and Infrared Spectroscopy of Polyvinylpyrrolidone/Multi-walled Carbon Nanotubes Nanocomposite

In this work, polyvinylpyrrolidone (PVP)/ Multi-walled carbon nanotubes (MWCNTs) nanocomposites were prepared with two concentrations of MWCNTs by casting method. Morphological, structural characteristics and electrical properties were investigated. The state of MWCNTs dispersion in a PVP matrix was indicated by Field Effect-Scanning Electron Microscopy (FESEM) which showed a uniform dispersion of MWCNTs within the PVP matrix. X-ray Diffraction (XRD) indicate strong bonding of carbonyl groups of PVP composite chains with MWCNTs. Fourier transfer infrared (FTIR) studies shows characteristics of various stretching and bending vibration bands, as well as shifts in some band locations and intensity changes in others. Hall effect was studied to test the type of charge carriers which was shown to be P-type. The electrical conductivity was shown increased for the pure PVP and pure MWCNT from (2.047×10-5) (Ω.cm)-1 and (3.683×101) (Ω.cm)-1 to (2.51×102 and 2.36×102) (Ω.cm)-1for both concentrations of nanocomposites, which indicate the conductivity was enhancement by using the carbon nanotubes.

Low-operating temperature and remarkably responsive methanol sensors using Pt-decorated hierarchical ZnO structure

Highly responsive methanol sensors working at low temperatures are developed using hierarchical ZnO nanorods decorated by Pt nanoparticles. The sensing materials are fabricated following a 3-step process: electrospinning of ZnO nanofibers, hydrothermal growth of hierarchical ZnO nanorods on the nanofibers and UV-assisted deposition of Pt nanoparticles. The morphology, structure and properties of the materials are examined by field-effect scanning electron microscopy, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, UV–Vis absorption spectroscopy, and electrical measurements. The methanol sensing performance is investigated at different working temperatures in the range of 110 °C–260 °C. It is observed that the surface modification of the ZnO hierarchical nanorods by Pt nanoparticles results in a remarkable enhancement of the sensing response toward methanol, which can reach approximately 19 500 times higher than that of the unmodified ZnO nanorods-based sensor. In addition, this modification enables lower working temperatures with an optimum range of 140 °C–200 °C. Based on the achieved results, a methanol sensing mechanism of the Pt/ZnO structure is proposed.

Novel P2-Type Na0.66Fe0.5-2xMn0.5TixVxO2 Cathode for High-Capacity

Necessity of energy storage and battery production is soaring up day by day due to the growth of portable electronic devices and surging evolution of electric vehicles (EVs), plug-in-hybrid electric vehicles (PHEVs) and renewables. Lithium-ion battery (LIB) technology has been the primary choice for such applications due to its high-energy-density, high-stability, and longer cycle life. Albeit with all merits of LIB, the prime concern has been the scarcity of lithium in earth’s crust and depletion of lithium reserve due to its wide usage in batteries, resulting in a higher production cost. This has prompted battery researchers to search for new alternatives to LIB for energy storage applications. Sodium, in this respect, can be a viable solution as it is the sixth most abundant element and shares the same group with lithium in the periodic table. Sodium has similar structural and electrochemical working mechanisms of lithium. The pivotal factors hindering the deployment of the laboratory-based sodium-ion battery (SIB) technologies into the commercial energy storage market are low energy density compared to that of LIB, lower stability, lower ion-transport mechanism, and lower operating voltage. Improvement of overall electrochemical performance of cathode materials can be a game-changer as it affects the energy density, lifespan, and tolerance of batteries. In this research, a cobalt-free novel P2-type transition metal cathode Na0.66Fe0.5-2xMn0.5TixVxO2 was synthesized by doping NaFeMnO2 with vanadium and titanium for SIB battery applications. The cathode was synthesized based on a sol-gel reaction where citric acid was used as a chelating agent. A set of physicochemical analysis, including Field-Effect Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDAX) analysis, as well as electrochemical analysis like Cyclic Voltammetry and Galvanometric Charge/ Discharge were performed to understand the correspondence between layered transition metal oxide chemistry, surface morphology and electrochemical competence of the new material. The crystal structures of the pristine material and cathodes containing different percentages of doped vanadium and titanium were examined and lattice parameters were refined through X-ray Diffraction (XRD) and Rietveld analysis. These exhaustive structural and morphological comparisons were performed between the pristine and modified NaFeMnO2 (NFM) cathode structures, which provided insights on the effects of vanadium and titanium doping on stabilizing surface structures, reducing Jahn-Teller distortion, enhancing stability and capacity retention and promoting Na+ carrier transport mechanism.

Synthesis and study of carbon quantum dots (CQDs) for enhancement of luminescence intensity of CQD@LaPO4:Eu3+ nanocomposite

The carbon nanodots are the newly emerging areas of research which have applications in many fields such as sensors, catalysts, bioimaging etc. Their excellent photoluminescence emission in visible region has prompted many researchers to explore new synthesis routes and precursors for better quantum yield. In this work carbon quantum dots are synthesized by using aloe vera biomass by facile carbonization process. The aqueous solution of carbon quantum dots (CQDs) shows blue light emission upon excitation by 365 nm ultra violet radiation. The field effect scanning electron microscopy images showed CQDs as spherical quantum dots of the size around 10 nm. The transmission electron microscopy (TEM) bright field images confirmed the size of the CQDs. The CQDs thus prepared can be used for bioimaging of plant cells and as an ink for security printing applications. A CQD@LaPO4:Eu3+ nanocomposite has been prepared and its photoluminescence property has been studied. The increased photoluminescence intensity of composite can be attributed to Förster Resonance Energy Transfer (FRET) from CQDs to Eu3+.

An investigation of annealing and (Zn + Co) co-loading impact on certain physical features of nano-structured (CdO) thin films coated by a sol-gel spin coating process

Transparent conducting pure and (Co + Zn) co-loaded CdO films were coated by sol-gel spin coating technique with various (cobalt + Zinc) co-loading concentrations. XRD analysis explained the polycrystalline nature of the coated samples with cubic crystal structure along (111) plane being the preferential orientation. The surface morphology and thickness of the prepared thin-films were analyzed by Field Effect Scanning Electron Microscopy (FESEM) and cross-sectional FESEM, respectively. The RMS surface roughness was analyzed by Atomic Force Microscopy AFM measurements. The existence of Cd, Co, Zn, and O elements was confirmed by “Energy-dispersive X-ray Spectroscopy (EDS) spectra”. The red-shift of energy-gap from 2.76 eV to 2.20 eV was carried out by using the Tauc;s and Davis-Mott mathematical relations, in high absorption regions. The shifting from the n-type to p-type semiconductor behavior for the coated samples was estimated by 4 points probe and average Hall coefficient value sign.

Directionally Controlled Growth of Fe-Anchored Carbon Fibers by the Electrospinning Process

The utility fit, structurally controlled development of down-scaled products is a great boon to new upcoming device functions for various applications. Fe nanoparticle decorated carbon fibers created through electrospinning offer advancement opportunities due to their capacity for tunable porosity with a high surface to the volume aspect ratio, which enables efficient accessibility, resulting in better performance in device applications. Here, we report on the synthesis of Fe nanoparticle anchored polymer (PVA) fibers created using an electrospinning process followed by a carbonization process was performed at different temperatures of 500 °C, 600 °C, and 700 °C under an inert (Ar) atmosphere. An annealing process allows the formation of pristine Fe ions rather than oxide formation, and the polymer transforms into graphitate by abnormal decomposition in PVA, without changing its fibrous morphology. The fibrous structure with uniform distribution of Fe nanoparticles product was confirmed by scanning electron microscopy, field-effect scanning electron microscopy, scanning tunneling electron microscopy, and tunneling electron microscopy images.

Mg Defect Induced Ferromagnetic Ordering in Li-Doped MgO Nanostructures

Magnesium deficient Li-doped MgO nanostructures were fabricated by hydrothermal method to investigate their structural, electronic, and magnetic properties. X-ray diffraction study confirms the single-phase crystallinity and changing the Li concentration (2%, 4% & 6%) in the host matrix of MgO induced strain and increased the crystallite size. Field-effect scanning electron microscopy images show the change in morphology from flakes to prismatic type nanostructures with the variation in Li content. The increase in Mg defects with an increase in Li doping, elucidated by X-ray photoelectron spectroscopy, would be the plausible reason for origin of d0 ferromagnetism and can be explained through (Li1+–VMg–Li1+) exchange interaction mechanism. Also, this increase in Mg defects leads to an increase in the value of saturation magnetization and grain size as well. Furthermore, electron paramagnetic resonance measurements explored the concepts of g-value and line width which are related with Mg defects and super exchange interaction of paramagnetic ions.

Effect of Cu2+ substitution on structure, morphology, and magnetic properties of Mg-Zn spinel ferrite

Objective: To prepare Cu doped Mg0:5􀀀xCuxZn0:5Fe2O4 (x = 0.0, 0.05, 0.1, 0.15,0.2 and 0.25) spinel ferrites materials and study the structure, morphology, and magnetic properties. Methods: Cu doped Mg-Zn spinel ferrites are magnetic and highly resistive materials. They were synthesized by the method of solid-state reaction and characterized by x-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), andvibrating sample magnetometer (VSM) for their structural, compositional,morphological, functional properties. They are with spinel structure under Fd-3m space group. Their crystallite size was 44.58 nm to 31.02 nm range after calcined at 1000 oC. Their spinel structure was confirmed with FT-IR analysis, whose absorption bands were 598.84 – 580.40 cm-1 and 405.35 - 402.15 cm-1 range for higher and lower frequency, respectively. The value of coercivity is in the range 146.33 - 9.427 Oe with the variation of content. The lower values of the coercivity indicated the soft ferrimagnetic nature of the synthesized materials. Findings/ Application: Substitution of non-magnetic Cu2+ ions strongly influenced the structural and magnetic properties of magnesium ferrites. Keywords: Cu doped MgZn ferrite; XRD; FTIR; FESEM; Coercivity

Enrichment a Study of Structural, Optical and Dielectric Properties of Mowiol 4-88 (Pva) Filled Zno Nanocomposites

The use of ZnO nanoparticles in the fabrication of PVA (Mowiol 4-88) nanocomposites with different ‘x’ filling compositions through solvent casting technique leading to the enrichment of the host's physical properties is presented. The sol-gel approach synthesizes Zinc Oxide (ZnO) nanoparticles. The formation of ZnO nanoparticles of size 100 nm was confirmed through X-ray powder diffraction (XRD) and Field Effect Scanning Electron Microscope (FESEM) techniques. The XRD technique determines the appearance of nanocomposites and their structural properties. The improvement in filling concentration enhances the particle size up to 150 nm and percentage crystallinity by 41 % for optimum filler composition. The FTIR spectra demonstrate ZnO nanofillers' binding with OH group of host Mowiol 4-88 through intra or inter hydrogen bonding leading to a complex conformation. The optical studies indicate a decrease in the energy gap with the rise in filler composition up to 15 wt%, and frequency-dependent dielectric constant characterization shows the enhancement in the dielectric constant with an optimum filling concentration 15 wt% ZnO nanofillers. FESEM image confirms homogenous distribution and complex particle size of incorporated ZnO nanoparticles in the PVA matrix. HIGHLIGHTS ZnO nanoparticles with Fabrication of PVA (Mowiol 4-88) nanocomposites through solvent casting technique ZnO nanoparticles of size 100 nm was confirmed Filling concentration enhances the particle size and percentage crystallinity SEM and EDS illustrate ZnO nanofiller’s systematic distribution Dielectric measurements show that these fabricated polymeric composites are polar GRAPHICAL ABSTRACT

Modification in morphological, structural, photoluminescence and antibacterial properties of SnS and CdS thin films by cold plasma treatment

SnS and CdS thin films was synthesized by electrochemical method and then the effect of applying the cold plasma on its properties was investigated. The morphology and structural properties of thin films were studied before and after plasma treatment using Xray diffraction spectrum, field-effect scanning electron microscope, energy dispersive Xray spectrum, Time-resolved photoluminescence and atomic force microscope. Given the high potential of cold plasma in surface modification of materials, the amount of wettability and antibacterial properties of thin films in the presence of standard grampositive and gram-negative bacteria was compared before and after plasma treatment. Results show that the applying the plasma causes the significant changes in morphology, self-cleaning and antibacterial properties of SnS and CdS thin films

Structural and optoelectronic properties change in Bi/In2Se3 heterostructure films by thermal annealing and laser irradiation

The amorphous materials are sensitive to external radiations and thermal annealing that brings changes in their structural and optical properties for optoelectronic applications. The present report shows the amorphous to crystalline structure transformation in Bi/In2Se3 by energy radiation and thermal annealing that modifies the linear as well as the nonlinear optical properties. The thermally evaporated Bi/In2Se3 film was subjected to 2.35 eV energy irradiation and 150 °C thermal annealing. The structural transition was probed by XRD, which revealed the formation of BiSe, Bi4Se3, and Bi2Se3 phases by replacing indium with an average crystallite size of ∼20 nm. The diffusion of Bi into In2Se3 host matrix modified the interfacial region as noticed from the field effect scanning electron microscopy pictures. The linear and nonlinear optical constants were evaluated from the UV–Visible data that show a significant change in the irradiated and annealed films due to the new phases. The change in direct and indirect bandgap is explained on the basis of density of defect states and degree of disorder. The significant change in the refractive index brings more freedom in designing multifunctional optoelectronic devices. The σopt and σelect changed noticeably with heat and energy treatment. The high value of χ3 (18.81 × 10−10 esu) for the Bi/In2Se3 film decreased significantly to 3.68 × 10−10 and 2.13 × 10−10 esu for the annealed and irradiated film. All the optical parameter changes due to annealing and irradiation are confined between the two-host materials In2Se3 and Bi/In2Se3. The corresponding changes were also observed in Raman spectroscopy data. The tuning of these linear and nonlinear parameters is useful for optoelectronics and photovoltaics.

Impact of non-stoichiometry in the thermoelectric performance of polyol method prepared Cu1+xIn1−xS2 (x = −0.3, −0.2, −0.1, 0, 0.1, 0.2) nanowires

A significantly enhanced thermoelectric power factor at 320 K in a facile polyol method prepared non-stoichiometric Cu1+xIn1−xS2 (x = −0.3, −0.2, −0.1, 0, 0.1, 0.2) nanowires with traces of Cu2S has been demonstrated here. Rietveld refinement of powder XRD and Raman analysis confirm these. Field effect scanning electron microscopy (FESEM) study shows micron size CuInS2 spherical particles made up from 8.8 nm diameter with about 35 nm length nanowires. The dramatic increase in electrical conductivity and hence thermoelectric performance with increasing x is attributed to the formation of defects, Cu2S, and increase in carrier concentrations. The power factor reaches a high of 0.8 μW m−1 K−2 at 320 K and an electrical conductivity of 2800 S/m, which is about 35 and 250 times higher, respectively, than that of pure CuInS2 and hot-pressed Bi2S3 nanorods respectively at this temperature. These results expect high-power factor improvement for power production in the future.

Effect of deposition temperature on the properties of F and Ti co-doped zinc oxide films

ZnO + 1.5 wt.% TiO2 powder is calcined at [Formula: see text] and sintered at [Formula: see text] to prepare the Ti-doped ZnO ceramic target, and RF sputtering is used to deposit F and Ti co-doped ZnO (FTZO) films by introducing Ar + CF4 mixing gas (CF4 flow rate is 0.2%) into the deposition chamber. The deposition temperature is changed from room temperature to [Formula: see text], and the thicknesses of all deposited FTZO films are controlled at about 320 nm. After FTZO films are deposited, X-ray diffraction pattern is used to analyze their crystalline properties, field-effect scanning electron microscope is used to observe their surface morphologies and confirm their thicknesses. n&k analyzer is used to measure the transmittance spectra in the wavelength range of 300–1100 nm and we find that the absorption edge of FTZO films is shifted to lower wavelength as the deposition temperature increases. The optical energy band gap of FTZO films is calculated using the transmittance spectra and the electrical properties of FTZO films are measured using a Hall equipment. Finally, secondary-ion mass spectrometry is used to analyze the C, O, F, Si and Ti elements with different deposition temperatures for confirming the existence and distribution of [Formula: see text] ions and non-existence of C element.

Benzo[ghi]perylenetriimide derivatives as effective interfacial passivation and electron transporting layers for inverted perovskite solar cells

In this study, we synthesized three benzo[ghi]perylenetriimide (BPTI) derivatives—C4, C3A, and C3AI—having butyl, dimethylaminopropyl, and propylammonium iodide side chains, respectively, and applied them as electron-transport layers (ETLs) and interfacial layers for inverted planar perovskite solar cells (PSCs) and examined their ability to function as defect passivation agents. Our PSC structure was glass/indium tin oxide/NiOx/CH3NH3(MA) PbI3/BPTI/PCBM/BCP/Ag. We used X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, UV–Vis spectroscopy, X-ray diffraction spectroscopy, field-effect scanning electron microscopy, and atomic force microscopy to determine the optoelectronic properties of PSCs prepared with and without the BPTIs. We found that the BPTI derivatives interacted with the perovskite and altered its energy levels to enhance electron extraction in their respective devices. In particular, C3AI effectively passivated the surface defects of perovskite and decreased the interfacial resistance, thereby suppressing the hysteresis effect and improving the device performance. We obtained an optimized power conversion efficiency (PCE) of 20.3% for the C3AI-containing MAPbI3 device, with a remarkable fill factor of 80.0%—among the highest ever reported for an MAPbI3-based p-i-n PSC. Therefore, this paper provides a new strategy of using nonfullerene materials for dual functions (as ETLs and defect passivation) in PSCs.

ROS-Mediated Apoptosis Induced by BSA Nanospheres Encapsulated with Fruit Extract of Cucumis prophetarum in Various Human Cancer Cell Lines.

In recent decades, biodegradable polymeric nanoparticles have been used as a nanocarrier for the delivery of anticancer drugs. In the present study, we synthesize bovine serum albumin (BSA) nanospheres and evaluate their ability to incorporate a plant extract with anticancer activity. The plant extract used was the methanol fruit extract of Cucumis prophetarum, which is a medicinal herb. The fruit-extract-encapsulated BSA nanospheres (Cp-BSA nanospheres) were prepared using a desolvation method at various pH values of 5, 7, and 9. The nanosphere formulations were characterized using various techniques such as dynamic light scattering (DLS), ζ-potential, Fourier transform infrared spectroscopy (FTIR), and field-effect scanning electron microscopy (FESEM). The results show that the Cp-BSA nanospheres prepared at pH 7 were spherical with a uniform particle size, low polydispersity index (PDI), ζ-potential, and high entrapment efficiency (82.3%) and showed sustained release of fruit extract from Cp-BSA nanospheres in phosphate-buffered saline (PBS), pH 5. The anticancer activity was evaluated on A549, HepG2, MCF-7 cancer cell lines and HEK 293 normal cell lines. In vitro, antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, intracellular reactive oxygen species (ROS) production, and mitochondrial membrane potential were estimated. An in vitro cellular uptake study was performed using fluorescein isothiocyanate (FITC) dye at a different time of incubation, and DNA fragmentation was observed in a dose-dependent manner. The gene expression level of Bax and the suppression level of Bcl-2 were observed upon the treatment of Cp-BSA nanospheres. Thus, the Cp-BSA nanospheres triggered ROS-dependent mitochondrial apoptosis in different human cancer cell lines when compared to the noncancerous cell lines and could be used as a potential candidate for anticancer agents.

Fabrication and characterization of silicon nanowires with MACE method to influence the optical properties

We are presenting here fabrication of silicon (Si) nanowires (NWs) arrays by using Si (100) wafer as substrate, by metal assisted chemical etching (MACE) method. The Si-NWs growth on the Si wafer has been done by using etching time of 45 min in etching solution of hydrogen fluoride and hydrogen peroxide. X-ray diffraction (XRD) has been used for the structural analysis of NWs to estimate the crystalline size, micro-strain, dislocation density of fabricated nanostructures. The surface morphology of Si-NWs array has been studied through field effect scanning electron microscopy (FE-SEM). The optical properties like energy band gap of fabricated Si-NWs has been carried out through UV–Vis diffuse reflectance spectroscopy (UV DRS) and photoluminescence (PL) spectroscopy.

Influence of laser power and welding speed on dendrite structure growth of low power pulsed laser welded super alloy

The influence of different welding parameters like welding speed and laser power on microstructure and the mechanical properties of low power pulsed Nd: Yag laser welded Nickel based super alloy inconel 617 sheets of thickness 1.5 mm has been investigated. In the present study, the welding of the specimens was done in a single pass aimed to full depth penetration. The microstructure of the various samples at fusion zone and at heat affected zone was characterized by field effect scanning electron microscope (FESEM) while the weld size of the welded metal at different parameters were measured using optical microscope (OM). The microhardness in the various zones for the welded sample has also been investigated. The microhardness of the welded samples was compared with base metal after experimental observations. The XRD technique was used to analyze the crystallography of the material at (2θ degree). The material has been used for the present study because of its exceptional properties of heat resistant and corrosion resistant. The Nd: YAG pulsed laser has been used because of its overlapping factor during welding that reduces porosity in the weld zone.

Nanofabrication of Iron-Cobalt (FeCo) Alloy by Sol-gel Method

Background and Introduction: Metal oxides (MOs) have been extensively used in a large range of engineering and medical applications. Methods: FeCo nanoparticles (NPs) were successfully synthesized by the solgel method in the presence of a powerful reducing agent-sodium borohydride (NaBH4). The structure, morphology, and optical properties of NPs were analyzed by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) at room temperature. Results: The XRD spectrum showed the body center cubic (BCC) structure of the samples after heat treatment at 500 °C. The SEM analysis exhibited that the particle size of as-synthesized and annealed samples was approximately 40 nm and 22 nm, respectively. Conclusion: The TEM investigations showed the rod-shaped sample of annealed NPs. The optical studies of the FTIR analysis revealed the starching bound of Fe-Co at the frequencies of 673 cm-1, 598 cm-1, and 478 cm-1.