Tool For Material Analysis Research Articles

Current-voltage characteristics of 100-pixel 200-μm-square superconducting tunnel junction X-ray detector array

The superconducting tunnel junction (STJ) X-ray detector is an important tool for materials analysis because of its high energy resolution and high counting rate. In this work, the current-voltage (I-V) characteristics were investigated for a 100-pixel STJ array with a pixel size of 200 μm having a layer structure of Nb-Al/AlO x /Al-Nb and working at 0.3 K. The fabrication yield of the 200-μm STJ reached approximately 90%. A series of I-V curves for a single pixel in different cooling runs showed a discrete excess current, possibly due to the trapping of single fluxoids. With a reduction of the ambient magnetic field during cooling, larger STJ pixels can be used.

Multimodal approach to mineral identification: merging Laser-induced breakdown spectroscopy with Hyperspectral imaging

While laser-induced breakdown spectroscopy is often used as a standalone technique, recent years saw an increasing interest in their combination with additional techniques towards multimodal sensing solutions capable of enhancing the capabilities of this technological solution. In this work, we try to identify possible synergies that arise from merging the analysis of laser-induced breakdown spectroscopy with that from a hyperspectral scanning of the sample, comparing it with the performance of standalone solutions. Having investigated the multimodal approach for a case study involving the identification of lithium minerals, our preliminary results demonstrate that while both solutions can provide reasonable results for qualitative mineral identification, they feature advantages and disadvantages that shall be taken into further consideration. Nevertheless, when working in collaboration, the results enclosed suggest that an integrated tandem solution can be an interesting tool for material analysis for research and industrial applications, combining the best of both instruments.

Handheld NIR Spectral Sensor Module Based on a Fully-Integrated Detector Array.

For decades, near-infrared (NIR) spectroscopy has been a valuable tool for material analysis in a variety of applications, ranging from industrial process monitoring to quality assessment. Traditional spectrometers are typically bulky, fragile and expensive, which makes them unsuitable for portable and in-field use. Thus, there is a growing interest for miniaturized, robust and low-cost NIR sensors. In this study, we demonstrate a handheld NIR spectral sensor module, based on a fully-integrated multipixel detector array, sensitive in the 850–1700 nm wavelength range. Differently from a spectrometer, the spectral sensor measures a limited number of NIR spectral bands. The capabilities of the spectral sensor module were evaluated alongside a commercially available portable spectrometer for two application cases: to quantify the moisture content in rice grains and to classify plastic types. Both devices achieved the two sensing tasks with comparable performance. Moisture quantification was achieved with a root mean square error (RMSE) prediction of 1.4% and 1.1% by the spectral sensor and spectrometer, respectively. Classification of the plastic type was achieved with a prediction accuracy on unknown samples of 100% and 96.4% by the spectral sensor and spectrometer, respectively. The results from this study are promising and demonstrate the potential for the compact NIR modules to be used in a variety of NIR sensing applications.

Study of wave propagation in discontinuous and heterogeneous media with the dynamic lattice method

The development of a new dynamic lattice element method (dynamicLEM) as well as its application in the simulation of the propagation of body waves in discontinuous and heterogeneous media is the focus of this research paper. The conventional static lattice models are efficient numerical methods to simulate crack initiation and propagation in cemented geomaterials. The advantages of the LEM and the developed dynamic solution, such as simulation of arbitrary crack initiation and propagation, illustration and simulation of existing inherent material heterogeneity as well as stress redistribution upon crack opening, opens a new engineering field and tool for material analysis. To realize the time dependency of the dynamic LEM, the equation of motion of forced vibration is solved while using the Newmark-beta method and implementing the non-linear Newton–Raphson Jacobian method. The method validation is done according to the results of a boundary element method (BEM) in the plane P-SV-wave propagation within a plane strain domain. Further tests comparing the generated wave types, simulation and study of crack discontinuities as well as inherent heterogeneities in the geomaterials are conducted to illustrate the accurate applicability of the new dynamic lattice method. The results indicate that with increasing heterogeneity within the material, the wave field becomes significantly scattered and further analysis of wave fields according to the wavelength/heterogeneity ratio become indispensable. Therefore, in a heterogeneous medium, the application of continuum methods in relation to structural health monitoring should be precisely investigated and improved. The developed dynamic lattice element method is an ideal simulation tool to consider particle scale irregularities, crack distributions and inherent material heterogeneities and can be easily implemented in various engineering applications.

Method for quantifying the reaction degree of slag in alkali-activated cements using deep learning-based electron microscopy image analysis.

In this paper, we present a methodology for measuring the reaction degree of ground granulated blast furnace slag (GGBFS) in alkali-activated cements using neural network based image analysis. The new methodology consists of an image analysis routine in which the segmentation of the back scattered electron (BSE) (SEM) images is based on a deep learning U-net. This methodology was applied to and developed for NaOH-activated slag cements and validated against independently measured XRD results. In a next step the developed method was applied to NaOH-Na2 SO4 -activated systems, to check the broader applicability. The neural networks based image analysis results were shown to correlate well with the XRD results. Once the model was trained, it segmented images fast and accurately. Furthermore, the model trained on the NaOH-activated systems was readily applicable on NaOH-Na2 SO4 -activated system indicating that the model generalises well. As such, the developed methodology and models can be more performant and robust than conventional threshold-based image segmentation. The method's accuracy, replicability and transferability make it a promising tool for material analysis and characterisation.

A Comprehensive Review on Raman Spectroscopy Applications

Raman spectroscopy is a very powerful tool for material analysis, allowing for exploring the properties of a wide range of different materials. Since its discovery, Raman spectroscopy has been used to investigate several features of materials such carbonaceous and inorganic properties, providing useful information on their phases, functions, and defects. Furthermore, techniques such as surface and tip enhanced Raman spectroscopy have extended the field of application of Raman analysis to biological and analytical fields. Additionally, the robustness and versatility of Raman instrumentations represent a promising solution for performing on-field analysis for a wide range of materials. Recognizing the many hot applications of Raman spectroscopy, we herein overview the main and more recent applications for the investigation of a wide range of materials, such as carbonaceous and biological materials. We also provide a brief but exhaustive theoretical background of Raman spectroscopy, also providing deep insight into the analytical achievements.

Analysis of Ancient Glass Using Ion Beams and Related Techniques

Ion Beam Analysis (IBA) techniques are established as an indispensable tool for material analysis. They are very powerful when applied to the examination of uniform layers. In recent years they have been also used for the quality control of implanted layers, which improve the mechanical or chemical properties of common materials. The use of IBA techniques for the study of corrosion is impeded by the non-uniformity of such layers, which renders the analysis difficult. In the Material Analysis Laboratory of the Institute of Nuclear Physics, a combination of experimental techniques and analytical algorithms has been developed, which allows the non-destructive examination of corrosion layers on cultural artifacts. Ancient glass fragments from Kenchreai, Greece, were analyzed with ion beam techniques, in order to examine the applicability of the latter to the characterization of the surface. The relative distribution of heavy components was determined by X-Ray Fluorescence (XRF). Nuclear reactions were used to determine the depth distribution of H, O, C and Si. The Hydrogen distribution rises sharply from the surface, reaching a maximum of 9xl022 at/cm3 at 0.5 μπι and then decays smoothly to a depth of approximately 2 μπα. Examination of the same samples with aparticles, indicates a depletion of Silicon in the same surface region, while the Oxygen distribution is uniform. A detailed analysis, using the 28Si(p, p) reaction, which resonates at 2.095 MeV, confirms the depletion and other non-uniformities in the Silicon distribution.

Design of 500 MHz RFQ linear accelerator for a compact neutron source, RANS-III

A compact neutron source using a particle accelerator is a promising tool for material analysis, infrastructural diagnostics, fissile material detection, and medical applications. For non-destructive, on-site inspection of the degradation of aged concrete and steel reinforcement it is essential to develop a light and compact neutron source system. To design a more compact RFQ linac for a transportable neutron source, we developed a 500 MHz RFQ linac.In this paper the design of a 500 MHz RFQ linac for a compact neutron source is described. First, using beam tracking simulation software, we designed the cell parameters of the 500 MHz RFQ linac, which can accelerate a proton beam from 30 keV to 2.49 MeV. Then, using three-dimensional electromagnetic simulation software and multiphysics simulation software, we optimized the cavity design of the 500 MHz RFQ linac, and investigated the thermal properties of the cavity with the cooling channels.

Moving Towards Ubiquitous Spectral Sensing

Material analysis tools have long been an important asset for research and production in a range of domains and markets, and have transformed our knowledge, development and quality control capabilities over time. Academic teams use material analysis for assessing composition and detection of chemicals in disciplines ranging from archaeology to medicine, food analysis, agricultural research, and biotech.

On the Influence of Delay Line Uncertainty in THz Time-Domain Spectroscopy

Terahertz time-domain spectroscopy (THz TDS) is a well-known tool for material analysis in the terahertz frequency band. One crucial system component in every time-domain spectrometer is the delay line which is necessary to accomplish the sampling of the electric field over time. Despite the fact that most of the uncertainty sources in TDS have been discussed, the delay line uncertainty has not been considered in detail. We model the impact of delay line uncertainty on the acquired THz TDS data. Interferometric measurements of the delay line precision and THz time-domain data are used to validate the theoretical model.

Sensitivity of Signal-to-Noise Ratio to the Layer Profile and Crystal Quality of SiGe/Si Multilayers

This study presents signal-to-noise ratio (SNR) measurements of single crystalline dots or layers of SiGe/Si in multilayer structures in terms of Ge content, interfacial and layer quality. All multilayers were processed in form of mesas and the noise behavior of electrical signal was investigated by comparing the power spectral density curves and K1/f values. The SiGe/Si multilayer structures were also characterized by the conventional material analysis tools and the results were compared to the noise measurements. The quality of SiGe/Si interface or SiGe layer was monitored by intentional exposure to oxygen in range of 2–1600 nTorr either during or prior to SiGe growth. The results demonstrated that SNR was sensitive to the interfacial and layer quality, and the Ge content in a multilayer structure. The noise level became very high when the strain fluctuated within SiGe layer and this occurred for SiGe with high Ge content or SiGe dots.

Simulation and experimental characterization of polymer/carbon nanotubes composites for strain sensor applications

In this paper, a numerical model is presented in order to analyze the electrical characteristics of polymer composites filled by carbon nanotubes (CNTs) subject to tensile stress and investigate the possible usage of such materials as innovative sensors for small values of strain. The simulated mechano-electrical response of the nanocomposite is obtained through a multi-step approach which, through different modeling stages, provides a simple and effective tool for material analysis and design. In particular, at first, the morphological structures of the composites are numerically simulated by adopting a previously presented model based on a Monte Carlo procedure in which uniform distributions of the CNTs, approximated as of solid cylinders and ensuring some physical constraints, are dispersed inside a cubic volume representing the polymer matrix. Second, a geometrical analysis allows to obtain the percolation paths detected in the simulated structures. Suitable electrical networks composed by resistors and capacitors associated to the complex charge transport and polarization mechanisms occurring in the percolation paths are then identified. Finally, the variations of these circuit parameters, which are differently affected by the mechanical stresses applied to the composites, are considered to analyze the electromechanical characteristics of the composites and hence their performances as stress sensors. The proposed approach is used to investigate the impact on the electro-mechanical response of some physical properties of the base materials, such as the type of carbon nanotube, the height of energy barrier of polymer resin, as well as characteristics of the composite, i.e., the volume fraction of the filler. The tunneling effect between neighboring nanotubes is found to play a dominant role in determining the composite sensitivity to mechanical stresses. The simulation results are also compared with the experimental data obtained by performing stress tests on samples of a multi walled CNT filled composite based on poly (ε-caprolactone), a polymer which is of interest for its biocompatibility. Model simulations and measured data show generally satisfactory agreement, confirming the effectiveness of the proposed approach to account for the impact of the interactions between CNTs and the insulating resin on the electromechanical response of the composite.

Energy-Dispersive Residual Stress Analysis under Laboratory Conditions: Concept for a New Type of Diffractometer

In the past decade energy-dispersive (ED) synchrotron diffraction has evolved into a powerful tool for materials analysis. Recording complete diffraction patterns in rather few different measuring directions allows for depth-resolved analysis not only of the near-surface residual stress state, but also of composition and even texture gradients. However, since the number of synchrotron beamlines dedicated to ED-diffraction is restricted to very few instruments, alternatives have to be found which allow for ED residual stress analysis even under low flux laboratory conditions. In this project we start to establish the scientific basis for a measuring and evaluation method to make the transfer of the ED method to the laboratory dimensions possible, which is adapted to the conditions of much lower photon flux and larger beam divergences of laboratory X-ray sources. In this paper, we present the concept of an ED-diffractometer which is equipped with two detectors to enable simultaneous data acquisition for two orientations of the diffraction vector with respect to the sample reference system. The first constructive and experimental steps are presented and furthermore the possibilities and limitations of the new laboratory method and the advantages of the ED diffraction method to realize short measurement times in order to realize a high resolution of information depth are discussed.

Laser induced breakdown spectroscopy (LIBS) as a rapid tool for material analysis

Laser induced breakdown spectroscopy (LIBS) is a novel technique for elemental analysis based on laser-generated plasma. In this technique, laser pulses are applied for ablation of the sample, resulting in the vaporization and ionization of sample in hot plasma which is finally analyzed by the spectrometer. The elements are identified by their unique spectral signatures. LIBS system was developed for elemental analysis of solid and liquid samples. The developed system was applied for qualitative as well as quantitative measurement of elemental concentration present in iron slag and open pit ore samples. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064 nm on test samples to study the capabilities of LIBS as a rapid tool for material analysis. The concentrations of various elements of environmental significance such as cadmium, calcium, magnesium, chromium, manganese, titanium, barium, phosphorus, copper, iron, zinc etc., in these samples were determined. Optimal experimental conditions were evaluated for improving the sensitivity of developed LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively couple plasma emission spectroscopy (ICP). Limit of detection (LOD) of our LIBS system were also estimated for the above mentioned elements. This study demonstrates that LIBS could be highly appropriate for rapid online analysis of iron slag and open pit waste.

The Potential of Materials Analysis by Electron Rutherford Backscattering as Illustrated by a Case Study of Mouse Bones and Related Compounds

Electron Rutherford backscattering (ERBS) is a new technique that could be developed into a tool for materials analysis. Here we try to establish a methodology for the use of ERBS for materials analysis of more complex samples using bone minerals as a test case. For this purpose, we also studied several reference samples containing Ca: calcium carbonate (CaCO(3)) and hydroxyapatite and mouse bone powder. A very good understanding of the spectra of CaCO(3) and hydroxyapatite was obtained. Quantitative interpretation of the bone spectrum is more challenging. A good fit of these spectra is only obtained with the same peak widths as used for the hydroxyapatite sample, if one allows for the presence of impurity atoms with a mass close to that of Na and Mg. Our conclusion is that a meaningful interpretation of spectra of more complex samples in terms of composition is indeed possible, but only if widths of the peaks contributing to the spectra are known. Knowledge of the peak widths can either be developed by the study of reference samples (as was done here) or potentially be derived from theory.

Synchrotron X-Rays for Microstructural Investigations of Advanced Reactor Materials

X-rays from synchrotron beamlines provide a powerful tool for materials analysis in circumstances where long-term materials degradation under complex loading conditions (e.g., temperature, irradiation, and stress) becomes important. This may occur for advanced gas cooled reactors. Synchrotron X-rays can help to improve lifetime assessments by providing a more in-depth understanding of microstructural damage. This article summarizes results of X-ray absorption fine spectrum analysis and X-ray magnetic circular dichroism synchrotron techniques. They were employed to evaluate various microstructural features, which are important in understanding the lifetime of materials exposed to extreme conditions. Dispersoid strengthening by yttria particles, conditions that produce nanocrystal Zircaloy, and the role of magnetism on the stability of ferritic steels were taken as examples.

X-ray microanalysis with microcalorimeters

The combination of high-energy-resolution spectrometers with high-spatial-resolution scanning electron microscopes provides a powerful tool for material analysis. X-ray spectrometers based on superconducting transition edge sensors combine the advantages of commonly used energy- and wavelength-dispersive spectrometers, i.e. a fast spectrum acquisition and a high-energy-resolution over a wide energy range. While the energies of the characteristic lines present in a spectrum contain the qualitative composition of the analyzed material, the corresponding mass fractions can be obtained from their intensities. In this work first quantitative measurements performed with the POLARIS spectrometer system are presented.

Work Function Microscopy as a Tool for Materials Analysis

Work Function Microscopy as a Tool for Materials Analysis

Simplifying position-sensitive gas-ionization detectors for heavy ion elastic recoil detection

Heavy ion elastic recoil detection is an effective tool for materials analysis. This has been facilitated by the development of novel detection systems, including large solid-angle gas-ionization detectors with position-sensitivity. With such detectors the exposure of the sample to the beam is reduced, however, data analysis can be complex. This paper reports on a detailed investigation of a detector design commonly used. The results of this work have led to suggestions for design-modifications, which considerably simplify detector operation and data analysis. The modifications have been implemented and tested. With the modified detector, the total energy information can be obtained by adding the signals from the anode electrodes, but also directly from a grid-electrode, obviating the need for the relative calibration of the anode electrodes. The subdivision of the energy loss electrode, together with a carefully chosen position of the entrance window to maintain optimum resolution for two ΔE signals, enable light and heavy ions to be resolved at the same gas pressure. The placement of a sawtooth electrode within the anode gives position information, which is linear and independent of atomic number and ion energy. Protons can be identified simultaneously with heavy ions by combining the information from the grid and residual energy signals, both amplified with high gain.

Quantitative Powder X‐ray Diffractometry Phase Analysis of Silicon Nitride Materials by a Multiline, Mean‐Normalized‐Intensity Method

A general purpose multiline, mean‐normalized‐intensity (MNI) method, derived from a procedure proposed in the literature, was applied to puase‐composition analysis of powders containing α‐ and β‐silicon nitride and small amounts of free silicon. Results obtained using peak and integrated intensities to derive the MNI values for the phases were compared with values determined by Rietveld pattern fitting according to error assessments based on the MNI standard deviation estimates calculated by assuming that the MNI data for each phase follow Gaussian statistics, and Rietveld‐derived standard deviations. The MNI results for the integrated intensities agreed reasonably with the Rietveld determinations and were discernibly superior to results obtained with peak intensities. The study demonstrated the power of the MNI method as a general tool for materials analysis.