Energy Dispersive X-ray Spectroscopy Spectra Research Articles

Model-Fitting Weighted Least Squares as an Alternative to Principal Component Analysis for Analyzing Energy-Dispersive X-ray Spectroscopy Spectrum Images.

Spectrum imaging with energy-dispersive X-ray spectroscopy (EDS) has become ubiquitous in material characterization using electron microscopy. Multivariate statistical methods, commonly principal component analysis (PCA), are often used to aid analysis of the resulting multidimensional datasets; PCA can provide denoising prior to further analysis or grouping of pixels into distinct phases with similar signals. However, it is well known that PCA can introduce artifacts at low signal-to-noise ratios. Unfortunately, when evaluating the benefits and risks with PCA, it is often compared only against raw data, where it tends to shine; alternative data analysis methods providing a fair point of comparison are often lacking. Here, we directly compare PCA with a strategy based on (the conceptually and computationally simpler) weighted least squares (WLS). We show that for four representative cases, model fitting of the sum spectrum followed by WLS (mfWLS) consistently outperforms PCA in terms of finding and accurately describing compositional gradients and inclusions and as a preprocessing step to clustering. Additionally, we demonstrate that some common artifacts and biases displayed by PCA are avoided with the mfWLS approach. In summary, mfWLS can provide a superior option to PCA for analysis of EDS spectrum images as the signal is simply and accurately modeled.

Zinc oxide-based sensor prepared by modified sol–gel route for detection of low concentrations of ethanol, methanol, acetone, and formaldehyde

Abstract We4 4 We received the acceptance date as 26 September 2024. Could you please update it to reflect this exact date for our project, instead of 1 October 2024? This is very important for our project funding. successfully synthesized zinc oxide (ZnO) nanoparticles using the sol–gel method, followed by their application onto alumina substrates for sensor testing. Comprehensive characterization of the nanomaterials was carried out utilizing XRD, SEM, TEM, UV–VIS-IR, and Photoluminescence (PL) techniques. The nanoparticles displayed a hexagonal wurtzite crystal structure, typical of ZnO. UV–Vis-IR spectroscopy revealed significant absorption in the UV region, with the band gap energy calculated to be 3.22 eV. PL spectra indicated the presence of various defects, such as oxygen vacancies and zinc interstitials, within the ZnO structure. SEM analysis of the deposited film surface showed spherical agglomerates, confirming the nanoscale dimensions, while energy-dispersive x-ray spectroscopy spectra affirmed the high purity of the ZnO films, rich in Zn and O elements. Sensor tests demonstrated the ZnO sensor’s high sensitivity to low concentrations of volatile organic compounds such as ethanol, formaldehyde, methanol, and acetone. Notably, at an operational temperature of 300 °C, the sensor exhibited a remarkable response to 5 ppm of each gas, with the following response and response/recovery times: for methanol, 11.47 and 36 s/57 s; for acetone, 11.54 and 25 s/52 s; for formaldehyde, 0.79 and 53 s/58 s; and for ethanol, 3.88 and 9 s/59 s.

Halogen-doped 2D reduced graphene oxide with TiO2 nanocomposite for water remediation application

Water contamination by organic and inorganic pollutants has been a challenging problem impacting living organisms. The current study explores the photocatalytic property of nanocomposite based on iodine-doped reduced graphene oxide with titanium dioxide nanoparticles (TNPs) for methyl orange (MO) dye degradation. A nanocomposite of TNPs with iodine-doped reduced graphene oxide (TIR) is prepared using the hydrothermal technique. The physicochemical properties of nanocomposite were explored by various techniques such as an X-diffractometer (XRD), Raman spectroscopy, Fourier transforms the infrared spectrum, energy-dispersive X-ray spectroscopy spectrum (EDX), and high-resolution transmission electron microscopy (HRTEM). The XRD reveals the crystalline structure of the TIR nanocomposite. The anatase TNPs with an average particle size of 9.68 ± 2.1 nm are confirmed by HRTEM. The Raman spectrum confirms the presence of iodine molecules with a peak at 101 cm−1, and the EDX spectrum confirms the presence of iodine molecules with 15.31 % elements in the TIR nanocomposite. The MO dye degradation efficiency of 96.12 % with 120 min UV exposure for TIR suggests that the iodine-doped nanocomposite is a promising photocatalyst for water remediation.

Synthesis and Properties of Eu and Ni Co-Doped ZnS Nanoparticles for the Detection of Ammonia Gas

Zinc sulfide nanoparticles were synthesized successfully via chemical co-precipitation, both in undoped form and co-doped with Europium (Eu) and Nickel (Ni). All prepared samples exhibited cubic zinc blende structure as confirmed by X-ray diffraction (XRD). The average particle size ranged from 3 to 6 nm for both pure and (Eu, Ni) co-doped ZnS, with no alteration in the crystal structure due to Eu and Ni co-doping. However, increasing the Ni dopant concentration (0, 2, 4, & 6 at%) while maintaining a constant Eu concentration (4 at%) led to an enhancement in the crystallite size. This was further validated by transmission electron microscopy (TEM), which showed particle sizes consistent with the XRD findings (3–5 nm). Microscopic analysis via scanning electron microscopy and TEM revealed spherical agglomerated morphology for the (Eu, Ni) co-doped nanoparticles. Energy-dispersive X-ray spectroscopy spectra confirmed the stoichiometric chemical composition of ZnS: Eu, Ni. Photoluminescence studies demonstrated an increased intensity of green luminescence at 6 at% Ni co-dopant concentration. Moreover, the synthesized samples exhibited promising gas sensing properties, particularly towards ammonia gas, with good selectivity. Notably, both pure and (Eu, Ni) co-doped ZnS nanoparticles showed rapid response and recovery times at room temperature, suggesting their potential applicability in gas sensing applications.

In Situ Liquid Cell Transmission Electron Microscopy Study of Studtite Particle Formation and Growth via Electron Beam Radiolysis.

This study presents in situ observations of studtite (UO2O2(H2O)2·2H2O) crystal growth utilizing liquid phase transmission electron microscopy (LP-TEM). Studtite was precipitated from a uranyl nitrate hexahydrate solution using hydrogen peroxide formed by the radiolysis of water in the TEM electron beam. The hydrogen peroxide (H2O2) concentration, directly controlled by the electron beam current, was varied to create local environments of low and high concentrations to compare the impact of the supersaturation ratio on the nucleation and growth mechanisms of studtite particles. The subsequent growth mechanisms were observed in real time by TEM and scanning TEM imaging. After the initial precipitation reaction, a post-mortem TEM analysis was performed on the samples to obtain high-resolution TEM images and selected area electron diffraction patterns to investigate crystallinity as well as energy-dispersive X-ray spectroscopy spectra to ensure that studtite was produced. The results reveal that studtite particles form through various mechanisms based on the concentration ratio of uranyl to H2O2 and that studtite is initially produced through an amorphous intermediary prior to formation of the crystalline material commonly reported in the literature.

Prediction of static failure in metal inert gas welded nuclear grade pipe 347 SS: Experimentation and finite-element analysis approach

Defect repair, one of primary concerns in the maintenance system for pipelines and other high strength components, is crucial in improving the reliability and economic benefits. Even though modern industries use several welding techniques to join metals, metal inert gas (MIG) welding is frequently preferred to weld stainless steel components by producing strong joints at high speed. In this study, MIG welding was used to butt weld 347 SS pipes. Research related to material failure is critical to engineers in order to find suitable application. Tensile test provides the static behavior of material. Therefore, predicting the strength and failure of material helps in satisfying industrial needs. Finite-element analysis (FEA) is an efficient technique to predict physical phenomenon virtually, therefore reducing the need for real-time prototypes. Johnson-Cook (J-C) material failure model is utilized to define failure in FEA model. Error percentage obtained while comparing FEA and experimental results of weld metal is 1.03%. Presence of niobium carbide is evident through the line map of energy-dispersive X-ray spectroscopy spectrum which prevents knife line attack through retarding chromium carbide precipitation at high temperature cycles. Welded samples with tensile strength of 583 ± 3 MPa exhibit better mechanical strength than base metal with tensile strength of 575 ± 2.5 MPa. This change in mechanical properties is caused by microstructural variation led by occurrence of constitutional supercooling while melt-pool solidifies. Failure mechanism of ductile fracture is understood from fractography (Tensile sample). Hence, this study provides a complete knowledge on failure mechanism of MIG-welded nuclear grade steel pipe under static loading. The failure mechanisms are explained in terms of FEA (J-C model) and fractography.

Green synthesis and characterization of silver nanoparticles to improve antibacterial activity using C. fenestratum leaf extracts

In this study, the silver nanoparticles have been green synthesized using C.fenestratum. Synthesized silver nanoparticles have been preliminary validated by the color change to rusty brown from greenish yellow and UV spectroscopy. Morphological analysis through FE-SEM showed cubic and spherical shape of synthesized nanoparticles and the diameter of the synthesized nanoparticles range from 30.18 to 184.89nm.The (EDS) energy-dispersive x-ray spectroscopy spectrum has confirmed the synthesis of AgNPs .The peaks around 400 cm ?1to 600 cm ?1in the IR spectrum indicated the vibration of metals- oxygen (Ag-O), whereas band at 1365.60 cm ?1 and 1357.89 cm ?1 shows the hydroxyl group bending which confirms the synthesis of nanoparticles. The silver nanoparticles exhibited antibacterial activity against E.coli with 20±0.3 mm (Zone of inhibition).

Synthesis under Normal Conditions and Morphology and Composition of AlF3 Nanowires.

AlF3 has interesting electrophysical properties, due to which the material is promising for applications in supercapacitors, UV coatings with low refractive index, excimer laser mirrors, and photolithography. The formation of AlF3-based nano- and micro-wires can bring new functionalities to AlF3 material. AlF3 nanowires are used, for example, in functionally modified microprobes for a scanning probe microscope. In this work, we investigate the AlF3 samples obtained by the reaction of initial aluminum with an aqueous hydrofluoric acid solution of different concentrations. The peculiarity of our work is that the presented method for the synthesis of AlF3 and one-dimensional structures based on AlF3 is simple to perform and does not require any additional precursors or costs related to the additional source materials. All the samples were obtained under normal conditions. The morphology of the nanowire samples is studied using scanning electron microscopy. We performed an intermediate atomic force microscope analysis of dissolved Al samples to analyze the reactions occurring on the metal surface. The surface of the obtained samples was analyzed using a scanning electron microscope. During the analysis, it was found that under the given conditions, whiskers were synthesized. The scale of one-dimensional structures varies depending on the given parameters in the system. Quantitative energy-dispersive x-ray spectroscopy spectra are obtained and analyzed with respect to the feedstock and each other.

Plasma-optimized contact for high-performance PdSe2 nanoflake-based field-effect transistors

Low-resistance contact has long been pursued in the two-dimensional (2D) electronic/optoelectronic device community. Still, an economy-efficient method highly compatible with the conventional 2D device fabrication process in laboratory remains to be explored. Herein, we report a plasma-optimized contact strategy for high-performance PdSe2 nanoflake-based field-effect transistors (FETs). Selenium vacancies created by air plasma can introduce p-type doping in the contact area, thus optimizing the device performance. The effect of plasma treatment on PdSe2 nanoflake is corroborated by high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy spectrum, atomic force microscopy, and Kelvin probe force microscopy. The PdSe2 FET with plasma-optimized contact exhibits significantly improved field-effect carrier mobilities, current on/off ratios, and reduced contact resistance than that without plasma treatment fabricated from the same PdSe2 nanoflake. Moreover, this strategy has also been proven effective to prepare high-performance FETs based on 2D WSe2 and MoSe2 nanoflakes, further demonstrating its application prospect.

Selective thermal neutron transmutation doping with Gd masks in GaN semiconductors

For the first time, selective neutron transmutation doping was successfully performed on GaN through Gd masks, showing the feasibility of patternable doping through neutron irradiations. In collaborating with Oak Ridge National Laboratory, GaN with Gd masks was irradiated by directional neutrons. By using the Gd properties with high neutron absorption cross-sections, it was confirmed that the area covered by Gd masks on GaN was completely shielded from neutrons, and the uncovered area was doped with the generated Ge and 14C. Property differences were clearly identified in various ways when comparing the area exposed by neutrons and the area unexposed by neutrons. The discoloration by the ejected protons and elastic scattering of neutrons appeared only in the exposed area while the unexposed area remained the same as before irradiation. The aspect ratio of the patterned profile of GaN was estimated by comparing patterns on the front and backside. From energy dispersive X-ray spectroscopy spectra and secondary ion mass spectrometry measurement, the concentration difference between Ge and 14C as well as the exact concentration of produced 14C was also checked. Schottky barrier diodes on the selectively doped GaN were fabricated and investigated to study the electrical properties.

Investigation of microstructure evolution and mechanical properties of gas tungsten arc welded dissimilar titanium (CP-Ti/Ti–6Al–4V) alloys

Economical welding of dissimilar titanium alloys has always been a challenge for the aerospace and nuclear industries, where these alloys are extensively used because of their high strength-to-weight ratio. The present investigation deals with the development of a novel shielding setup for the successful welding of commercially pure titanium (α-phase) to Ti–6Al–4V ((α + β)-phase) without any atmospheric contamination using gas tungsten arc welding. Commercially pure titanium (CP-Ti) and Ti–6Al–4V sheets of 3 mm thickness were butt-welded autogenously and using CP-Ti filler metal. Metallographic studies, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, microhardness measurements, tensile testing, and fractography were carried out to understand the evolution of the microstructure and characterize the welds. Grain coarsening in heat-affected zone and weld, and variation in the distribution of phases were observed from the optical micrographs and energy-dispersive X-ray spectroscopy spectrum of different zones. An unsymmetrical variation of hardness was observed in the weld region, and a 15% reduction in hardness value (280 HV0.2) was obtained at the weld center of using filler metal weld than autogenous weld. Comparable strengths with little drop from as-received CP-Ti (307 MPa) were observed for welded specimens. Welds produced using CP-Ti filler metal (272 MPa) had higher strength than autogenous welds (214 MPa). As-received tensile specimens fractured nearly from the center of gauge length, but welded tensile specimens fractured near the base/heat-affected zone boundary of the CP-Ti side.

Electrochemical 3D printing of Ni–Mn and Ni–Co alloy with FluidFM

Additive manufacturing can realize almost any designed geometry, enabling the fabrication of innovative products for advanced applications. Local electrochemical plating is a powerful approach for additive manufacturing of metal microstructures; however, previously reported data have been mostly obtained with copper, and only a few cases have been reported with other elements. In this study, we assessed the ability of fluidic force microscopy to produce Ni–Mn and Ni–Co alloy structures. Once the optimal deposition potential window was determined, pillars with relatively smooth surfaces were obtained. The printing process was characterized by printing rates in the range of 50–60 nm s−1. Cross-sections exposed by focused ion beam showed highly dense microstructures, while the corresponding face scan with energy-dispersive x-ray spectroscopy spectra revealed a uniform distribution of alloy components.

Food-Borne Nanocarriers for Calcium Delivery: A New Choice for Nutrient Supplements.

Calcium is considered as an important nutrient element for the maintenance of human health, and food-borne nanoparticles (FNs) produced during food processing may have potential as nanocarriers for calcium ion delivery. Beef is an important source of animal protein that has high protein and low fat content and is rich in a variety of amino acids; thus, beef may be a suitable material for the development of calcium nanocarriers. In this paper, FNs were synthesized from beef by one-step hydrothermal synthesis. The FNs had a spherical shape with a size of about 3.0 nm and emitted a bright blue fluorescence under 365 nm ultraviolet irradiation. The amino nitrogen atom and carboxyl oxygen atom of the functional groups on the surface of the FNs were the main binding sites for the chelation of Ca(II). The size of the FNs-Ca(II) complex was about 4.75 nm, and the specific signal peak of calcium at 3.7 keV was observed in its energy dispersive X-ray spectroscopy spectrum. The viability of cells treated with FNs-Ca(II) was more than 65%, while viability was only 60% after treatment with CaCl2. The results showed that the FNs from beef have great potential in calcium delivery for the development of a calcium supplement.

Observations of supermicron-sized aerosols originating from biomass burning in southern Central Africa

During the 3 years of the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) campaign, the NASA Orion P-3 was equipped with a 2D stereo (2D-S) probe that imaged particles with maximum dimension (D) ranging from 10 < D < 1280 μm. The 2D-S recorded supermicron-sized aerosol particles (SAPs) outside of clouds within biomass burning plumes during flights over the southeastern Atlantic off Africa’s coast. Numerous SAPs with 10 < D < 1520 μm were observed in 2017 and 2018 at altitudes between 1230 and 4000 m, 1000 km from the coastline, mostly between 7–11° S. No SAPs were observed in 2016 as flights were conducted further south and further from the coastline. Number concentrations of refractory black carbon (rBC) measured by a single particle soot photometer ranged from 200 to 1200 cm−3 when SAPs were observed. Transmission electron microscopy images of submicron particulates, collected on Holey carbon grid filters, revealed particles with potassium salts, black carbon (BC), and organics. Energy-dispersive X-ray spectroscopy spectra also detected potassium, a tracer for biomass burning. These measurements provided evidence that the submicron particles originated from biomass burning. NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) 3 d back trajectories show a source in northern Angola for times when large SAPs were observed. Fire Information for Resource Management System (FIRMS) Moderate Resolution Imaging Spectroradiometer (MODIS) 6 active fire maps showed extensive biomass burning at these locations. Given the back trajectories, the high number concentrations of rBC, and the presence of elemental tracers indicative of biomass burning, it is hypothesized that the SAPs imaged by the 2D-S are examples of BC aerosol, ash, or unburned plant material.

WO3/CoWO4 nanocomposite synthesis using a facile co-precipitation method for enhanced photocatalytic applications

In this work, pure tungsten oxide (WO3) nanoparticles (NPs) and WO3/CoWO4 nanocomposites (NCs) with various cobalt concentrations from 5 to 20 wt% were prepared via a co-precipitation process and subsequent annealing at 600 °C. All the synthesized samples were characterized by different techniques to study their structural, morphological, elemental, and optical properties and also to verify the conversion of WO3 NPs to WO3/CoWO4 NCs. X-ray diffraction results confirmed the existence of a stable monoclinic phase for pure WO3 NPs and that no phase change occurs even after the formation of CoWO4. The average crystallite sizes calculated for pure WO3 NPs and 20 wt% WO3/CoWO4 NCs were approximately 34 and 17 nm, respectively. Field-emission scanning electron microscopy revealed that pure WO3 consists of nanoparticles as well as some nanoplates of size in the 30 nm diameter range. On Co doping of WO3, the size seems decrease and reveals very small NPs of size below 20 nm. Energy-dispersive X-ray spectroscopy spectra showed the persistence of chemical elements and their amount before and after the inclusion of cobalt. The chemical composition and the oxidation state of the elements on the surface of the synthesized NPs and NCs were investigated by X-ray photoelectron spectroscopy. The type of functional groups and their corresponding vibrational modes were identified by Fourier transform infrared spectroscopy. UV–visible studies were used to calculate the bandgap (Eg) of pure WO3 NPs and WO3/CoWO4 NCs by means of Kubelka-Munk function plots. There was a reduction in Eg from 2.61 eV for pure WO3 NPs to 2.51 eV for 20 wt% Co NCs. In photoluminescence studies, the intensity of the emission peaks of WO3/CoWO4 NCs showed a decreasing trend in comparison with pure WO3 NPs. The formation of WO3/CoWO4 NCs effectively controls the charge carrier (electron-hole) recombination. Hence, an appreciable enhancement in the photocatalytic degradation of the toxic dye methylene blue (C16H18N3SCl) of up to 86.5% was accomplished with WO3/CoWO4 NCs (20 wt% Co sample) under irradiation with a UV-A light source.

Plasma-exposed TiO2 nanoparticles on polyethylene terephthalate matrix surface and its effects on the durable hydrophobic coating

Commercial dull polyethylene terephthalate (PET) fabric treated by radio frequency (13.56 MHz) plasma and further coated with perfluoroalkyl methacrylate copolymer C6 displays much highly durable hydrophobicity and oleophobicity. The as-prepared fabric exhibited a water contact angle above 170°, a water spray rating of 80 (ISO 3), and oil resistance ratings of B and C separately for different oil composition grades after 10 washing cycles, which were two levels higher than the untreated and C6-coated PET[TiO2] fabric. The organic component PET was more prone to etching than TiO2, which created a waviness structure and exposed prominent TiO2 nanoparticles on the PET fiber surface. The relative atom ratio O and Ti increased through energy-dispersive X-ray spectroscopy spectra and X-ray photoelectron spectroscopy analysis. This result indicates that the exposure of TiO2 and the introduction of reactive polar groups such as O=C-O on the fiber surface contributed to react with C6 and improved the washing durability. In general, such coating technology may provide a simple benign technique for constructing materials with physicochemical properties.

Experimental studies on ablation characteristics of alumina after irradiation with a 193-nm ArF excimer laser

Laser ablation of alumina ceramics was performed in the ambient air using a 193-nm ArF excimer laser. The effect of the laser parameters (pulse repetition frequency, laser spot diameter, fluence, and the number of laser pulses) on the ablation behavior was investigated. Scanning electron microscopy, optical microscopy, Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDS) were used to assess the crater morphology, ablation depth, and changes in the structure and chemical composition of the ablated material. There was no significant difference in the ablation rate between craters produced at a pulse repetition frequency of 10 and 100 Hz using a number of laser pulses up to 500. Increasing pulse repetition frequency to 300 Hz slightly reduced the ablation rate of the craters produced using > 150 laser pulses. The ablation rate was found to decrease from pulse to pulse at high fluence and was higher for small (25 µm) than for large (110 µm) laser spot diameters. The Raman and EDS spectra, collected at and near the ablated craters, were similar to those collected at pristine non-ablated areas, indicated no changes in the structure and chemical composition of alumina due to ablation. Ablation threshold fluence was calculated from the relationship between ablation rate and fluence for craters produced using 60 laser pulses and was found to be 1.35 J/cm2.

Strain mediated enhancement in magnetoelectric properties of sonochemically synthesized piezoelectric and piezomagnetic composites

Materials with magneto-electric (ME) properties are of great importance because of their demand in electronic industries. Three dimensional nano-particles of the ME-composites having the general formula (1-x)CoCr0.3Fe1.7O4(CCFO)+(x)BaTiO3(BTO) (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were obtained by comprising the piezoelectric-BTO and piezomagnetic-CCFO phases. The individual phases of CCFO and BTO were synthesized separately by ultrasonic irradiation assisted sonochemical and sol-gel routs. X-ray diffraction patterns (XRD) confirmed the well-crystalline nature of both the phases. BTO and CCFO phases were under tensile strain as confirmed by the variation in lattice constants with varying proportion of BTO and CCFO. An energy-dispersive X-ray spectroscopy spectrum confirmed the phase purity of the samples and stoichiometric concentration of elements. Magnetic properties were investigated by M − H loop measurements and dielectric properties by using RF impedance analyzer. Dielectric constant increased with the increasing percentage of BTO. The maximum value of ME coefficient (24.7 mV/cm⋅Oe) is observed for the 60%CCFO+40%BTO sample. The obtained results were discussed in the light of grain size, strain and the basic properties of the individual phases. The prepared materials can be applicable in electronic devices where high magneto-electric coefficient is desirable.

Optical properties of biosynthesized nanoscaled Eu2O3 for red luminescence applications.

This contribution reports on the optical properties of biosynthesised Eu2O3 nanoparticles bioengineered for the first time by a green and cost effective method using aqueous fruit extracts of Hyphaene thebaica as an effective chelating and capping agent. The morphological, structural, and optical properties of the samples annealed at 500°C were confirmed by using a high-resolution transmission electron microscope (HR-TEM), x-ray diffraction analysis (XRD), UV-Vis spectrocopy, and photoluminescence spectrometer. The XRD results confirmed the characteristic body-centered cubic (bcc) structure of Eu2O3 nanoparticles with an average size of 20 nm. HR-TEM revealed square type morphology with an average size of ∼6nm. Electron dispersion energy dispersive x-ray spectroscopy spectrum confirmed the elemental single phase nature of pure Eu2O3. Furthuremore, the Fourier transformed infrared spectroscopy revealed the intrinsic characteristic peaks of Eu-O bond stretching vibrations. UV-Vis reflectance proved that Eu2O3 absorbs in a wide range of the solar spectrum from the VUV-UV region with a bandgap of 5.1 eV. The luminescence properties of such cubic structures were characterized by an intense red emission centered at 614 nm. It was observed that the biosynthesized Eu2O3 nanoparticles exhibit an efficient red-luminescence and hence a potential material as red phosphor.

Tribological performance of non-asbestos brake friction material in contact with brake disc of varying topography

PurposeThe purpose of this paper is to evaluate experimentally the influence of different surface roughness of the contacting disc on tribological performance of the non-asbestos brake friction material (BFM).Design/methodology/approachTaguchi method was applied to design an experiment using three different discs of gray cast iron with different surface roughness, which is measured using optical profilometer. These discs were subjected to sliding against pins prepared with the developed non-asbestos BFM, using pin on disc friction and wear monitor.FindingsThe experimental results shows that the disc 2 (Ra = 3.77µm) gives wear of 22.78µm and coefficient of friction of 0.462, which is recommended for extreme brake performance. Analysis of Taguchi design revealed that the disc surface was most significant parameter among the parameters under study.Practical implicationsDuring braking, continuous sliding between the BFM and brake disc or drum not only results into wear of BFM but also changes the surface finish of the brake drum or disc. This leads to variation in surface topography of the drum or disc surface with application of brakes, which further affects the characteristics of the BFM.Originality/valueThe tribological performance of BFM depends upon the topography of the surface on which it was sliding. To get best performance of the non-asbestos friction materials, disc having moderate surface finish is recommended. Scanning electron microscope micrographs had shown the different plateaus formed and energy-dispersive X-ray spectroscopy spectra identified presence of different chemical elements prior to sliding of the pins surface over different discs surface topography.Peer reviewThe peer review history for this article is available at:https://publons.com/publon/10.1108/ILT-04-2020-0120/