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14 pages, 609 KiB

Open AccessArticle

Comparison of Electron Compton Scattering with Positron Compton Scattering in Polyethylene

by Maurizio Dapor

Materials 2025, 18(7), 1609; https://doi.org/10.3390/ma18071609 - 2 Apr 2025

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Abstract

Understanding the interaction of charged particles with polymers is crucial for applications in materials science, radiation physics, and electron spectroscopy. This study investigates the differences in the elastic scattering spectra of electrons and positrons in polyethylene, focusing on the underlying mechanisms that influence [...] Read more.

Understanding the interaction of charged particles with polymers is crucial for applications in materials science, radiation physics, and electron spectroscopy. This study investigates the differences in the elastic scattering spectra of electrons and positrons in polyethylene, focusing on the underlying mechanisms that influence the spectral features. The analysis isolates key factors such as recoil energy, Doppler broadening, and the interplay between elastic and inelastic mean free paths. Using Monte Carlo simulations, we analyze the effects of the elastic and inelastic mean free paths on the intensity of the elastic peaks in an energy range from 1000 eV to 3000 eV. The results show that the elastic peaks are consistently more intense for electrons than for positrons, correlating with the differences in the respective elastic scattering cross sections. In addition, we evaluate the effects of different inelastic mean free path models on spectral variations and compare the simulated data showing how variations in inelastic mean free path values affect the intensity of elastic peaks and the elastic reflection coefficient of polyethylene. The percentage difference in the elastic reflection coefficients of electrons and positrons in polyethylene decreases from 49% to 24% when the incident particle energy increases from 1000 eV to 3000 eV. These findings contribute to a refined understanding of the interactions of electrons and positrons with polymers, improve the accuracy of Monte Carlo simulations, and promote methods for material characterization. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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24 pages, 2085 KiB

Open AccessArticle

Metaheuristics Algorithm-Based Optimization for High Conductivity and Hardness CuNi₂Si₁ Alloy

by Jarosław Konieczny, Krzysztof Labisz, Satılmış Ürgün, Halil Yiğit, Sinan Fidan, Mustafa Özgür Bora and Ş. Hakan Atapek

Materials 2025, 18(5), 1060; https://doi.org/10.3390/ma18051060 - 27 Feb 2025

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Abstract

The optimization of CuNi₂Si₁ alloy’s mechanical and electrical properties was achieved through a combination of experimental approaches and metaheuristic algorithms. Optimizing hardness and electrical conductivity through a variation in aging temperature (450–600 °C) and aging duration (1–420 min) was taken [...] Read more.

The optimization of CuNi₂Si₁ alloy’s mechanical and electrical properties was achieved through a combination of experimental approaches and metaheuristic algorithms. Optimizing hardness and electrical conductivity through a variation in aging temperature (450–600 °C) and aging duration (1–420 min) was taken under consideration in the present work. Cold rolling with 50% strain after solution annealing aided in microstructure refinement and accelerated Ni₂Si precipitates’ development, and property improvement increased. Optimum temperature and holding period were 450 °C and 30 min, respectively, with 266 HV and 13 MS/m and 167 HV and 11.2 MS/m for non-deformed samples, respectively. SPBO, genetic algorithm (GA), and particle swarm optimization (PSO) metaheuristic algorithms were considered, and SPBO exhibited the best prediction accuracy. SPBO predicted 450 °C for 61.75 min, and experimental testing exhibited 267 HV and 14 MS/m, respectively. Polynomial regressions with 0.98 and 0.96 values for R² confirmed these values’ accuracy. According to this work, computational optimization proves effective in optimizing development and property tailoring for application in industries including aerospace and electrical engineering. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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18 pages, 8695 KiB

Open AccessArticle

Ordered Mesoporous Silica Prepared with Biodegradable Gemini Surfactants as Templates for Environmental Applications

by Sarvarjon Kurbonov, Martin Pisárčik, Miloš Lukáč, Zsolt Czigány, Zoltán Kovács, István Tolnai, Manfred Kriechbaum, Vasyl Ryukhtin, Viktor Petrenko, Mikhail V. Avdeev, Qiang Tian, Ana-Maria Lacrămă and László Almásy

Materials 2025, 18(4), 773; https://doi.org/10.3390/ma18040773 - 10 Feb 2025

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Abstract

Mesoporous silica sieves have been prepared through sol–gel synthesis using diester gemini surfactants as pore templates, aiming to obtain new materials with potential use for water remediation. A series of mesoporous spherical silica particles of submicron size have been prepared in an alkali-catalyzed [...] Read more.

Mesoporous silica sieves have been prepared through sol–gel synthesis using diester gemini surfactants as pore templates, aiming to obtain new materials with potential use for water remediation. A series of mesoporous spherical silica particles of submicron size have been prepared in an alkali-catalyzed reaction, using a tetraethyl orthosilicate precursor and bis-quaternary ammonium gemini surfactants with diester spacers of varied lengths as pore-forming agents. The effect of the spacer length on the particle morphology was studied using nitrogen porosimetry, small-angle X-ray scattering (SAXS), ultra-small-angle neutron scattering, scanning, and transmission electron microscopy (SEM, TEM). The results revealed that for all spacer lengths, a long-range hexagonal pore ordering developed in the materials. The silica particles were nearly spherical, with sizes below 1 micrometer, and a weak dependence of the mean particle size on the spacer length could be observed. The template removal procedure had a strong influence on the porosity: calcination caused a moderate shrinkage of the pores while retaining the hexagonal structure, whereas treatment with acidified ethanol resulted in only partial removal of the surfactants; however, the hexagonal structure was severely destroyed. The applicability of the obtained calcined materials as adsorbents for heavy metal ions from water was studied with the example of Pb(II). A high sorption capacity of 110 mg/g was obtained in batch experiments, at pH 5 and 4 h contact time. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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24 pages, 12593 KiB

Open AccessArticle

Non-Invasive Raman and XRF Study of Mīnā’ī Decoration, the First Sophisticated Painted Enamels

by Philippe Colomban, Gulsu Simsek Franci, Anh-Tu Ngo and Xavier Gallet

Materials 2025, 18(3), 575; https://doi.org/10.3390/ma18030575 - 27 Jan 2025

Viewed by 802

Abstract

Mīnā’ī wares, crafted during the 12th–13th centuries, represent some of the earliest examples of sophisticated painted enamel decoration by potters. Due to the thinness of these enamel layers, their detailed characterization remains challenging, even with the use of advanced techniques, such as Proton-Induced [...] Read more.

Mīnā’ī wares, crafted during the 12th–13th centuries, represent some of the earliest examples of sophisticated painted enamel decoration by potters. Due to the thinness of these enamel layers, their detailed characterization remains challenging, even with the use of advanced techniques, such as Proton-Induced X-ray Emission (PIXE) analysis and Rutherford Backscattering Spectrometry (RBS). This study provides the first combined non-invasive analysis, using X-ray fluorescence (XRF) and Raman spectroscopy, of five shards attributed to mīnā’ī wares. For comparison, two İznik shards from the 17th century, which feature similarly styled but thicker enamel decorations, were also analyzed. Interestingly, the mīnā’ī paste was found to contain lead and tin, suggesting the use of a lead-rich frit in its composition. This finding was confirmed through micro-destructive analysis, using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM–EDS). Elements, such as rubidium (Rb), strontium (Sr), yttrium (Y), and zirconium (Zr), produced significant XRF signals and effectively distinguished mīnā’ī wares from İznik wares. A uniform tin-rich glaze, measuring 300–500 µm in thickness, was used as a base layer for the much thinner painted mīnā’ī enamels. The colored areas (blue, turquoise, red, green, black, white, eggplant) revealed the presence of various coloring agents and phases, such as spinels, chromite, and ions like Cu²⁺ and Co²⁺, as well as opacifiers like cassiterite and lead–calcium/potassium arsenates. Two distinct cobalt sources were identified: one associated with arsenic and the other with manganese and nickel. These cobalt sources are comparable to those used in İznik pottery. For the first time, boron was detected in the blue enamel of mīnā’ī wares. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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19 pages, 4024 KiB

Open AccessArticle

Spectroscopic and Morphological Examination of Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd) Obtained by Glycine Nitrate Procedure

by Milena Rosić, Maja Milošević, Maria Čebela, Vladimir Dodevski, Vesna Lojpur, Uroš Čakar and Srecko Stopic

Materials 2025, 18(2), 397; https://doi.org/10.3390/ma18020397 - 16 Jan 2025

Viewed by 644

Abstract

The glycine nitrate procedure (GNP) is a method that proved to be the easiest and most effective method for controlling the composition and morphology during the synthesis of Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd). This method of the [...] Read more.

The glycine nitrate procedure (GNP) is a method that proved to be the easiest and most effective method for controlling the composition and morphology during the synthesis of Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd). This method of the combustion process achieves control of stoichiometry, homogeneity, and purity. Metal nitrates and glycine were mixed in the appropriate stoichiometric ratios to produce Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd). The samples obtained by the mentioned method were further subjected to different characterization methods such as differential thermal analyses (DTA), X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), spectroscopy, field emission scanning electron microscopy (FESEM), and nitrogen adsorption method. A high level of anisotropy of the shape and size of particles in the form of agglomerates was found. Also, there are noticeable differences in the microstructure and plate crystals. The color of the synthesized sample changes from darker to lighter shades after thermal treatments. There are pronounced changes in the dominant wavelength (nm) and color purity between the initial sample and the sample after heating (1100 °C) due to the concentration of Co. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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28 pages, 13465 KiB

Open AccessEditor’s ChoiceArticle

Innovative Approaches on the Estimation of the Effective Permittivity of Fibrous Media

by Jesus Nain Camacho Hernandez and Guido Link

Materials 2025, 18(1), 14; https://doi.org/10.3390/ma18010014 - 24 Dec 2024

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Abstract

Estimating the effective permittivity of anisotropic fibrous media is critical for advancing electromagnetic applications, requiring detailed microstructural and orientation analyses. This study introduces innovative approaches for disclosing the orientation and microstructure of fibers, leading to mixing relations. It particularly focuses on two specific [...] Read more.

Estimating the effective permittivity of anisotropic fibrous media is critical for advancing electromagnetic applications, requiring detailed microstructural and orientation analyses. This study introduces innovative approaches for disclosing the orientation and microstructure of fibers, leading to mixing relations. It particularly focuses on two specific fiber configurations: 1. wave-curved fibers and 2. a collection of interconnected fibers. The first approach uses sinusoidal wave fibers, considering their curvature and direction. Conversely, the approach for the interconnected fibers operates on the principle of representing fibers as a collection of straight segments. Investigations on fibrous media for both approaches were performed using numerical calculations at the microwave frequency of 2.45 GHz. Each fibrous medium was treated as an effective medium by using fibers significantly smaller than the microwave wavelength. A thorough comparison was made between the proposed mixing relations, numerical data, and state-of-the-art mixing relations to assess their consistency and validity. The comparison of the proposed approaches with traditional models shows an improved accuracy of up to 70% and 8% for the real and imaginary components of the permittivity, respectively. Additionally, the root-mean-square errors were determined as 0.001 + j0.003 and 0.001 – j0.007 for the sinusoidal and interconnected straight fibers approaches, respectively. In addition, a woven alumina fabric was used to compare the experimental resonance frequency with that from simulations using the permittivity of the fabric estimated by the interconnected straight fibers approach. These findings advance the predictive accuracy of permittivity estimation in fibrous media, providing a robust foundation for engineering applications. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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15 pages, 3706 KiB

Open AccessEditor’s ChoiceArticle

Chemical Compositions and Chromatic Mechanism of High-Temperature Iron-Series Glazed Wares from the Guangyuan Kiln in Sichuan Province, Southwest China During the Song Dynasty

by Lin Wu, Yourongtian Nie, Jinwei Li, Junming Wu, Wei Shi, Yanfang Wu and Yueguang Jiang

Materials 2024, 17(24), 6221; https://doi.org/10.3390/ma17246221 - 19 Dec 2024

Viewed by 571

Abstract

The Guangyuan kiln, located in the Sichuan Province, Southwest China during the Song Dynasty (960–1279 A.D.), is renowned for its high-temperature iron-series glazed wares, including pure black glazed ware, hare’s fur glazed ware, glossy brown glazed ware, and matte brown glazed ware. To [...] Read more.

The Guangyuan kiln, located in the Sichuan Province, Southwest China during the Song Dynasty (960–1279 A.D.), is renowned for its high-temperature iron-series glazed wares, including pure black glazed ware, hare’s fur glazed ware, glossy brown glazed ware, and matte brown glazed ware. To elucidate the raw materials, processing techniques, and coloration mechanisms of these wares, multiple analytical experiments were employed to investigate chemical composition, microstructure, and the phase of Fe-bearing minerals. We found that glossy brown glazed ware has the highest Fe₂O₃ content in the glaze (7.67 wt% on average), while pure black glazed ware exhibits the lowest (4.84 wt% on average). Higher Fe₂O₃ content leads to more iron for Fe-bearing mineral crystallization and larger ε-Fe₂O₃ precipitation. Based on microscopic observations, pure black glazed ware has numerous 100–250 nm crystalline grains, while hare’s fur glaze ware features dendritic crystal flowers (200–400 nm), which exhibited liquid-liquid phase separation within the glaze, suggesting localized phase separation inducing iron oxide crystallization. Glossy brown glazed ware contains well-developed ε-Fe₂O₃ crystals (25 µm), and matte brown glazed ware, with the highest CaO and total flux, has acicular anorthite crystals alongside ε-Fe₂O₃ crystals. In summary, the decorative effect of four different types of iron-series glazed wares is determined by their chemical composition, phase composition, and microscopic structure. The findings offer valuable insights for the study of ancient iron-glazed ware. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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13 pages, 7271 KiB

Open AccessEditor’s ChoiceArticle

In Situ Analysis of Binder Degradation during Catalyst-Accelerated Stress Test of Polymer Electrolyte Membrane Fuel Cells

by Donggeun Yoo, Sujung Park, Sohyeong Oh, Minsoo P. Kim and Kwonpil Park

Materials 2024, 17(17), 4425; https://doi.org/10.3390/ma17174425 - 9 Sep 2024

Cited by 3 | Viewed by 1373

Abstract

High-oxygen-permeability ionomers (HOPIs) are being actively developed to enhance the performance and durability of high-power polymer electrolyte membrane fuel cells (PEMFCs). While methods for evaluating binder performance are well-established, techniques for assessing binder durability and measuring its degradation in situ during the AST [...] Read more.

High-oxygen-permeability ionomers (HOPIs) are being actively developed to enhance the performance and durability of high-power polymer electrolyte membrane fuel cells (PEMFCs). While methods for evaluating binder performance are well-established, techniques for assessing binder durability and measuring its degradation in situ during the AST process remain limited. This study examines the distribution of relaxation times (DRT) and Warburg-like response (WLR) methods as in situ analysis techniques during the catalyst-accelerated stress test (AST) process. We conducted catalyst-ASTs (0.6–0.95 V cycling) for 20,000 cycles, monitoring changes using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Contrary to expectations, during the catalyst-AST, the ion transport resistance of the binder decreased, indicating no binder degradation. Scanning electron microscopy/energy dispersive spectrometer (SEM/EDS) analysis revealed that the degradation rate of the catalyst and the support was relatively higher than that of the binder, leading to a reduction in catalyst layer thickness and improved binder network formation. By applying the DRT method during the catalyst-AST process, we were able to measure the increase in oxygen reduction reaction (ORR) resistance and the decrease in proton transport resistance in situ. This allowed for the real-time detection of the reduction in catalyst layer thickness and improvements in ionomer networks due to catalyst and support degradation. These findings provide new insights into the complex interplay between catalyst degradation and binder performance, contributing to the development of more durable PEMFC components. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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16 pages, 10093 KiB

Open AccessArticle

Phase Transformation and Mechanical Optimization of Eggshell-Derived Hydroxyapatite across a Wide Sintering Temperature Range

by Shih-Ching Wu, Hsueh-Chuan Hsu, Mei-Yi Liu and Wen-Fu Ho

Materials 2024, 17(16), 4062; https://doi.org/10.3390/ma17164062 - 15 Aug 2024

Viewed by 1300

Abstract

Calcium phosphate, particularly hydroxyapatite (HA), bears a close resemblance to human bones, rendering it a prevalent material in biomedical applications. This study focuses on the successful preparation of HA using a precipitation method with eggshell as a raw material. Subsequently, the HA powder [...] Read more.

Calcium phosphate, particularly hydroxyapatite (HA), bears a close resemblance to human bones, rendering it a prevalent material in biomedical applications. This study focuses on the successful preparation of HA using a precipitation method with eggshell as a raw material. Subsequently, the HA powder was press-formed and sintered at various temperatures to investigate the impact of sintering temperature on the mechanical properties, including hardness, compressive strength, and fracture toughness, of the sintered HA samples (E-HA). Statistical analyses, including one-way ANOVA and Tukey’s post-hoc test, were conducted to determine significant differences in these properties at different sintering temperatures. Experimental findings revealed that as the sintering temperature increased, HA partially transformed into β-TCP between 800 and 1300 °C, with α-TCP observed at 1400 °C. The elimination of pores led to an increase in relative density, with a maximum relative density of 94.5% achieved at 1200 and 1300 °C. E-HA sintered at 1200 °C exhibited the highest hardness (5.08 GPa), compressive strength (255.79 MPa), and fracture toughness (1.21 MPa·m0.5). However, at 1400 °C, a slight decrease in apparent density (2.90 g/cm³) was noted due to the presence of α-TCP, along with significant grain growth. This study’s objective is clearly aligned with the study design, incorporating detailed statistical analyses to validate the findings. Furthermore, bacterial culture experiments were conducted using sintered E-HA, Chem-HA (HA synthesized from reagent-grade calcium carbonate), and Comm-HA (commercial HA). Streptococcus mutans was cultured on the surfaces of sintered E-HA, Chem-HA, and Comm-HA samples for 20 h. After culturing, the OD values for all samples were below 0.2, indicating significant antibacterial efficacy. The comparable OD values and bacterial counts (p > 0.05) suggest that the source of HA does not impact its antibacterial properties. This underscores the potential of eggshell-derived HA as an effective material for biomedical applications. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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17 pages, 3208 KiB

Open AccessArticle

Thermogravimetric/Thermal–Mass Spectroscopy Insight into Oxidation Propensity of Various Mechanochemically Made Kesterite Cu₂ZnSnS₄ Nanopowders

by Katarzyna Lejda, Janusz Partyka and Jerzy F. Janik

Materials 2024, 17(6), 1232; https://doi.org/10.3390/ma17061232 - 7 Mar 2024

Cited by 2 | Viewed by 1132

Abstract

Thermogravimetry coupled with thermal analysis and quadrupole mass spectroscopy TGA/DTA-QMS were primarily used to assess the oxidation susceptibility of a pool of nanocrystalline powders of the semiconductor kesterite Cu₂ZnSnS₄ for prospective photovoltaic applications, which were prepared via the mechanochemically assisted [...] Read more.

Thermogravimetry coupled with thermal analysis and quadrupole mass spectroscopy TGA/DTA-QMS were primarily used to assess the oxidation susceptibility of a pool of nanocrystalline powders of the semiconductor kesterite Cu₂ZnSnS₄ for prospective photovoltaic applications, which were prepared via the mechanochemically assisted synthesis route from two different precursor systems. Each system, as confirmed by XRD patterns, yielded first the cubic polytype of kesterite with defunct semiconductor properties, which, after thermal annealing at 500 °C under neutral gas atmosphere, was converted to the tetragonal semiconductor polytype. The TGA/DTA-QMS determinations up to 1000 °C were carried out under a neutral argon Ar atmosphere and under a dry, oxygen-containing gas mixture of O₂:Ar = 1:4 (vol.). The mass spectroscopy data confirmed that under each of the gas atmospheres, a distinctly different, multistep evolution of such oxygen-bearing gaseous compounds as sulfur oxides SO₂/SO₃, carbon dioxide CO₂, and water vapor H₂O was taking place. The TGA/DTA changes in correlation with the nature of evolving gases helped in the elucidation of the plausible chemistry linked to kesterite oxidation, both in the stage of nanopowder synthesis/storage at ambient air conditions and during forced oxidation up to 1000 °C in the dry, oxygen-containing gas mixture. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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13 pages, 3425 KiB

Open AccessArticle

Design of an Optical Device Based on Kirigami Approach

by Marta De Giorgi

Materials 2024, 17(5), 1211; https://doi.org/10.3390/ma17051211 - 6 Mar 2024

Cited by 1 | Viewed by 1141

Abstract

The aim of this work was to design a kirigami-based metamaterial with optical properties. This idea came from the necessity of a study that can improve common camouflage techniques to yield a product that is cheap, light, and easy to manufacture and assemble. [...] Read more.

The aim of this work was to design a kirigami-based metamaterial with optical properties. This idea came from the necessity of a study that can improve common camouflage techniques to yield a product that is cheap, light, and easy to manufacture and assemble. The author investigated the possibility of exploiting a rotation to achieve transparency and color changing. One of the most important examples of a kirigami structure is a geometry based on rotating squares, which is a one-degree-of-freedom mechanism. In this study, light polarization and birefringence were exploited to obtain transparency and color-changing properties using two polarizers and common cellophane tape. These elements were assembled with a rotating-square structure that allowed the rotation of a polarizer placed on the structure with respect to a fixed polarizer equipped with cellophane layers. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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21 pages, 5905 KiB

Open AccessArticle

Investigating the Behavior of Thin-Film Formation over Time as a Function of Precursor Concentration and Gas Residence Time in Nitrogen Dielectric Barrier Discharge

by Faegheh Fotouhiardakani, Alex Destrieux, Jacopo Profili, Morgane Laurent, Sethumadhavan Ravichandran, Gowri Dorairaju and Gaetan Laroche

Materials 2024, 17(4), 875; https://doi.org/10.3390/ma17040875 - 14 Feb 2024

Cited by 2 | Viewed by 1473

Abstract

This study aims to establish a correlation between the fragmentation process and the growth mechanisms of a coating deposited on a fluoropolymer. Deposition was carried out using dielectric barrier discharge at atmospheric pressure, employing an oxygen-containing organic precursor in a nitrogen environment. The [...] Read more.

This study aims to establish a correlation between the fragmentation process and the growth mechanisms of a coating deposited on a fluoropolymer. Deposition was carried out using dielectric barrier discharge at atmospheric pressure, employing an oxygen-containing organic precursor in a nitrogen environment. The findings reveal that the impact of precursor concentration on the formation of specific functionalities is more significant than the influence of treatment time. The X-ray photoelectron spectroscopy (XPS) results obtained indicate a reduction in the N/O ratio on the coating’s surface as the precursor concentration in the discharge increases. Fourier transform infrared spectroscopy (FTIR) analysis, conducted in the spectral range of 1500 cm⁻¹ to 1800 cm⁻¹, confirmed the connection between the chemical properties of plasma-deposited thin films and the concentration of organic precursors in the discharge. Furthermore, the emergence of nitrile moieties (C≡N) in the FTIR spectrum at 2160 cm⁻¹ was noted under specific experimental conditions. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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13 pages, 2095 KiB

Open AccessArticle

Application of the Van Cittert Algorithm for Deconvolving Loss Features in X-ray Photoelectron Spectroscopy Spectra

by Giorgio Speranza

Materials 2024, 17(3), 763; https://doi.org/10.3390/ma17030763 - 5 Feb 2024

Cited by 1 | Viewed by 1376

Abstract

The convolution of two physical entities, denoted as f and g, delineates the manner in which one entity undergoes modification in response to the other. This transformative process is mathematically represented by the expression f ⨂ g, symbolizing the convolution of [...] Read more.

The convolution of two physical entities, denoted as f and g, delineates the manner in which one entity undergoes modification in response to the other. This transformative process is mathematically represented by the expression f ⨂ g, symbolizing the convolution of the two entities in a resultant function h. Frequently, it becomes imperative to comprehend the magnitude of the induced modifications. From the derived function h, a crucial step involves the separation of the two original signals, a process commonly referred to as deconvolution. Various techniques have been proposed to facilitate the calculation of the deconvolution, with one notable approach originating in 1931 by van Cittert. The algorithm, based on an iterative method, has been scrutinized over time, notably by Bracewell and, more recently, by Jansson. This work represents the current state-of-the-art, focusing specifically on the analysis of Auger spectra obtained through XPS. Emphasis is placed on delineating the procedural aspects of the analysis, and the algorithm utilized in the open-source software RxpsG is comprehensively described. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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19 pages, 5269 KiB

Open AccessArticle

Study on the Influence of UV Light on Selective Antibacterial Activity of Silver Nanoparticle Synthesized Utilizing Protein/Polypeptide-Rich Aqueous Extract from The Common Walkingstick, Diapheromera femorata

by James Lee Cho, Luc Gaston Allain and Sanichiro Yoshida

Materials 2024, 17(3), 713; https://doi.org/10.3390/ma17030713 - 2 Feb 2024

Cited by 2 | Viewed by 1956

Abstract

Common walkingstick (Diapheromera femorata) aqueous extract (CWSAE) can induce the synthesis of useful bionanomaterials. CWSAE is rich in water-soluble organic compounds such as proteins and polypeptides that function as reducing/stabilizing agents for nanoparticle formation from Ag⁺ ion precursors. The synthesized [...] Read more.

Common walkingstick (Diapheromera femorata) aqueous extract (CWSAE) can induce the synthesis of useful bionanomaterials. CWSAE is rich in water-soluble organic compounds such as proteins and polypeptides that function as reducing/stabilizing agents for nanoparticle formation from Ag⁺ ion precursors. The synthesized AgNPs exhibited a moderately uniform size, with the majority falling within the range of 20–80 nm. These AgNPs were UV-treated and tested as antibacterial agents to inhibit the growth of four pathogenic bacteria (Burkholderia cenocepacia K-56, Klebsiella pneumoniae ST258, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus USA300), as well as one common bacterium (Escherichia coli BW25113). The disk diffusion test demonstrated that the UV-treated AgNPs significantly and selectively inhibited the growth of Staphylococcus aureus USA300 and P. aeruginosa, while showing a small effect on the other two species. This suggests the potential application of green-chemically synthesized AgNPs as selective antibacterial agents. Furthermore, we studied the effects of short-term (1–2 min) and long-term (5–30 min) UV treatment on the selective cytotoxicity of the AgNPs and found that the cytotoxicity of the AgNPs could depend on the duration of UV exposure against certain bacteria. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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18 pages, 10867 KiB

Open AccessArticle

Impact of Notches on Additively Manufactured Inconel 718 Tensile Performance

by Joseph Johnson and Daniel Kujawski

Materials 2023, 16(20), 6740; https://doi.org/10.3390/ma16206740 - 18 Oct 2023

Cited by 1 | Viewed by 1627

Abstract

This study was completed in effort to characterize the notch sensitivity of additively manufactured (AM) Inconel 718 produced by laser powder bed fusion (L-PBF). Three different root radii on V-notched test specimens and smooth specimens were evaluated under tensile conditions for specimens built [...] Read more.

This study was completed in effort to characterize the notch sensitivity of additively manufactured (AM) Inconel 718 produced by laser powder bed fusion (L-PBF). Three different root radii on V-notched test specimens and smooth specimens were evaluated under tensile conditions for specimens built in vertical and horizontal orientations. Both the total axial strain and localized notch diametral strain were measured. Finite element analysis (FEA) was completed on each specimen geometry to confirm the actual strain measurements near the notch. Test results showed the tensile strength of the notched specimens were larger than the tensile strength values of the smooth specimens. These tensile results equate to a notch-sensitivity ratio (NSR) greater than one, indicating that the L-PBF Inconel 718 material is a notch-strengthened material. It is suspected that the notch strengthening is a result of increased triaxial stress produced near the notch tip causing added material constraints, resulting in higher strength values for the notched specimens. Fractography analysis was completed on the various fracture surfaces and identified a dominate ductile failure mode within all of the specimens; however, the amount of ductility reduced with smaller notch root radii. While this study provides the initial notch responses of the L-PBF Inconel 718, further research must be completed in regard to the impact of notches on more complex loading behaviors, such as fatigue and stress-rupture conditions. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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Review

Jump to: Research

32 pages, 5550 KiB

Open AccessReview

Advances in Focused Ion Beam Tomography for Three-Dimensional Characterization in Materials Science

by Francesco Mura, Flavio Cognigni, Matteo Ferroni, Vittorio Morandi and Marco Rossi

Materials 2023, 16(17), 5808; https://doi.org/10.3390/ma16175808 - 24 Aug 2023

Cited by 11 | Viewed by 3274

Abstract

Over the years, FIB-SEM tomography has become an extremely important technique for the three-dimensional reconstruction of microscopic structures with nanometric resolution. This paper describes in detail the steps required to perform this analysis, from the experimental setup to the data analysis and final [...] Read more.

Over the years, FIB-SEM tomography has become an extremely important technique for the three-dimensional reconstruction of microscopic structures with nanometric resolution. This paper describes in detail the steps required to perform this analysis, from the experimental setup to the data analysis and final reconstruction. To demonstrate the versatility of the technique, a comprehensive list of applications is also summarized, ranging from batteries to shale rocks and even some types of soft materials. Moreover, the continuous technological development, such as the introduction of the latest models of plasma and cryo-FIB, can open the way towards the analysis with this technique of a large class of soft materials, while the introduction of new machine learning and deep learning systems will not only improve the resolution and the quality of the final data, but also expand the degree of automation and efficiency in the dataset handling. These future developments, combined with a technique that is already reliable and widely used in various fields of research, are certain to become a routine tool in electron microscopy and material characterization. Full article

(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization)

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The 15th Anniversary of Materials—Recent Advances in Advanced Materials Characterization

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