Effective Number Of Electrons Research Articles

Enhancing the radiation shielding performance of polyepoxide composites based on cement bypass dust

In this study, radiation shielding composite materials were created by combining epoxy with cement bypass dust (CBPD) at different weight percentages (0%, 10%, 20%, and 30%). The solution casting technique was employed to construct these materials. The FTIR spectra confirmed the formation of the composites and the production of complexes. The morphology and elemental content of the produced composite samples were illustrated using SEM pictures and EDX spectra. In addition, the research findings demonstrated that the composites exhibited improved resistance to changes in temperature as the loading of CBPD increased. The gamma-ray attenuation coefficients of composites consisting of Epoxy + x% CBPD exhibited an increase, along with an increase in the neutron removal cross-section. However, there was a gradual increase in both the mean free path (MFP) as well as the half value layer (HVL) with increasing energy. Additionally, the experimental and theoretical data for attenuation parameters were compared using the Phy-X/PSD software. The relationship between the effective atomic and electron numbers of the Epoxy + x% CBPD composites has been studied. The values of fast and thermal neutron attenuation were analyzed using the NGCal software. In general, these composites are appropriate for use in radiation shielding applications.

Enhancing gamma and neutron radiation shielding efficiency of LDPE/PVC polymers using cobalt, aluminum, and magnesium oxide fillers

A procedure for creating and assessing LDPE/PVC polymers using Co, Al, and Mg oxides as fillers for use as radiation shielding material was conducted. The SEM/EDX equipment was utilized for elemental analysis and mapping in order to visually represent the morphology of the produced polymers. The characterizations indicate that the MgCo2O4 particles possess an irregular and tiny morphology, displaying a spherical form with an average diameter of less than 100 nm. In addition, the Al2CoO4 particles are characterized as being aggregated, diminutive, and exhibiting a spherical morphology, with an average diameter of less than 150 nm. The current study involved experimental investigation, simulation using FLUKA-MC code, and theoretical calculations using Phy-X-PSD code to examine the radiological properties of the shielding material. The results depend on several factors, including the half-value layer (HVL), the effective atomic number (Zeff), the effective electron number (Neff), the effective conductivity (Ceff), the exposure buildup factor (EBF), the energy-absorption buildup factor (EABF), and the fast neutron macroscopic removal cross-section (FNRC). The SR-NIEL-7 platform has been utilized to compute the mass-stopping power for protons (H+) and alpha particles (He++) based on their kinetic energy. The experimental findings indicate that the density of LDPE/PVC filled with MgCo2O4 is greater than that of Al2CoO4. Furthermore, polymer filled with MgCo2O4 exhibits higher values for MAC, LAC, and FNRCs than Al2CoO4 filler. The measured LAC and MAC conform to the simulated values.

Gamma-enhancement of reflected light images as a routine method for assessment of compositional heterogeneity in common low-reflectance Fe-bearing minerals

Abstract Incorporation of impurity elements into minerals impacts on their physical properties (e.g., reflectance, hardness, and electrical conductivity) but the quantitative relationships between these features and compositional variation remain inadequately constrained. Prior work has shown that gamma-enhancement of reflected light images represents a simple yet powerful tool to assess the compositional heterogeneity of single pyrite crystals as it can enhance subtle differences in reflectance between distinct domains with different minor element concentrations. This study extends the gamma correction method to several other common Fe-bearing minerals, magnetite, garnet, wolframite, and tetrahedrite-tennantite, which all have far lower reflectance than pyrite. Gamma-enhanced optical images reveal clear variations in reflectance that are either systematic with increased minor element concentration as the change in gray value on backscatter electron (BSE) images (in the case of magnetite, garnet, and tetrahedrite-tennantite) or contrasting (as in pyrite), yielding a convincing linkage between reflectance variation and compositional heterogeneity. Reflectance variation is an expression of the distribution of the average effective number of free electrons on the mineral surface that can re-emit light when excited by visible light. Gamma-enhanced images can reveal compositional heterogeneity in minerals such as wolframite where small atomic mass differences between substituting elements (Mn and Fe, in the case of wolframite) are virtually impossible to observe as a variation of gray values on BSE images. Results also demonstrate that Fe-rich domains in these minerals can be expected to have higher reflectance than Fe-poor domains whenever Fe is a major constituent. The greater reflectance is attributed to Fe ions having a greater effective number of free electrons than many other elements (e.g., Co, Ni, Si, Ca, Al, Mg, Mn, and As). The research highlights the utility of gamma correction as an inexpensive tool for routine evaluation of compositional heterogeneity in common Fe-bearing minerals, potentially obviating the necessity of a microbeam platform to correlate textures and composition.

Fragmentation patterns of DNA-stabilized silver nanoclusters under mass spectrometry.

DNA-stabilized silver nanoclusters (AgN-DNAs) are emitters with tuneable structures and photophysical properties. While understanding of the sequence-structure-property relationships of AgN-DNAs has advanced significantly, their chemical transformations and degradation pathways are far less understood. To advance understanding of these pathways, we analysed the fragmentation products of 21 different red and NIR AgN-DNAs using negative ion mode electrospray ionization mass spectrometry (ESI-MS). AgN-DNAs were found to lose Ag+ under ESI-MS conditions, and sufficient loss of silver atoms can lead to a transition to a lesser number of effective valence electrons, N0. Of more than 400 mass spectral peaks analysed, only even values of N0 were identified, suggesting that solution-phase AgN-DNAs with odd values of N0 are unlikely to be stable. AgN-DNAs stabilized by three DNA strands were found to fragment significantly more than AgN-DNAs stabilized by two DNA strands. Moreover, the fragmentation behaviour depends strongly on the DNA template sequence, with diverse fragmentation patterns even for AgN-DNAs with similar molecular formulae. Molecular dynamics simulations, with forces calculated from density functional theory, of the fragmentation of (DNA)2(Ag16Cl2)8+ with a known crystal structure show that the 6-electron Ag16Cl2 core fragments into a 4-electron Ag10 and a 2-electron Ag6, preserving electron-pairing rules even at early stages of the fragmentation process, in agreement with experimental observation. These findings provide new insights into the mechanisms by which AgN-DNAs degrade and transform, with relevance for their applications in sensing and biomedical applications.

A Study of Photon Interaction Parameters for Some Stainless Steel Alloys

In this work, we investigated the effective atom number, the effective electron density, the mean free path, the tenth-value layer, the half-value layer, and the mass attenuation coefficient for some stainless steels: AISI 302, AISI 303, AISI 304, AISI 304L, AISI 310, AISI 316, AISI 321, and AISI 410. The mass attenuation coefficients were determined using the WinXCom computer program in the energy region 1keV- 100 GeV. The effective atom number and effective electron density have been calculated using two different methods, the direct method, and the interpolation method. The results reveal that the values of effective atomic numbers and effective electron numbers are greatly influenced by the atomic number of elements in the alloy and the interaction photon energy. The effective atom numbers grew as the atomic number of the constituents in the alloys increased. The effective atomic number and effective electron density values for all steels were found to have the highest values at 0–0.1 MeV energy and the lowest values in the 0.5–6 MeV energy range. The shielding properties of the steels produced close results, but AISI 304L provided the best protection while AISI 410 provided the least. The results obtained with both methods were also compared. The result of the present study may provide new and helpful knowledge about stainless steel for gamma-ray shielding applications.

A comprehensive analysis on radiation shielding characteristics of borogypsum (boron waste) by Phy-X/PSD code

In the present study, radiation shielding characteristics of the borogypsum, which is a waste generated during the boric acid production in Turkey, was analyzed. For this purpose, we used recently developed Phy-X/PSD software, which is provided to calculate shielding parameters such as mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth-value layer, effective atomic number, total atomic cross section, total electronic cross section, effective conductivity, effective electron number, buildup factors and fast neutron removal cross section in a wide photon energy range. Additionally, mass attenuation coefficients of borogypsum were compared with those of other radiation shielding materials (ordinary concrete, obsidian, pumice, clay) in order to give a significant evaluation about the radiation shielding capability of borogypsum. Half value layer and fast neutron removal cross section values are also evaluated by other materials. It is noticed that borogypsum has higher shielding potential than other reported shielding materials.

Radiation protection efficiency of newly produced W-based alloys: Experimental and computational study

Tungsten based alloy is one of the materials which has great attention and can be used as gamma-ray shields, radiation source collimator, spallation neutron source target, plasma facing materials, etc. The motivation of the study is to produce new tungsten based alloys and determine the radiation protection characteristics of the alloys that can be used for radiation related applications. In this context, five tungsten based alloys (WxTayCr10Ni10Fe10Mo10) were produced and the dependence of radiation shielding ability on the changes in W and Ta concentration was investigated. The photon protection parameters such as linear attenuation coefficients, mass attenuation coefficients, effective atomic number, mean free path, half-value layer, exposure and energy absorption buildup factors, effective conductivity, effective electron number, atomic and electronic cross sections, and fast neutron removal cross-sections of the alloys were determined by Phy-X/PSD code. Additionally, XRD, EPR and SEM-EDS experimental results were evaluated for the investigation of spectroscopic characteristics. The crystallite sizes of the alloys were calculated by Debye-Scherrer method depending on the XRD phases in order to perform the structural characterization. It is concluded that a relationship exists between the crystallite size and photon attenuation. It may be stated that the increase in the amount of W improves the gamma radiation protection efficiency of the alloys. It is also seen that the fast neutron attenuation feature increases proportionally with W content. It is determined that the tungsten based alloys can be used as good radiation protection materials in radiation related applications.

Novel flexible and lead-free gamma radiation shielding nanocomposites based on LDPE/SBR blend and BaWO4/B2O3 heterostructures

In the present work, flexible lead-free radiation shielding nanocomposite films based on low-density polyethylene (LDPE)/styrene butadiene rubber (SBR) doped with BaWO4/B2O3 heterostructures (0, 5, 10, 15, and 20 wt%) were fabricated using the melt blending method. XRD patterns and FTIR spectra revealed the successful preparation of the nanocomposite films and complexation. SEM images and EDX spectra were also used to illustrate the morphology and elemental composition of the prepared nanocomposite films. Furthermore, the research results showed enhanced thermal stability of the nanocomposite films with increased BaWO4/B2O3 loading. The mass attenuation coefficient (MAC) values for LDPE/SBR+20 wt% BaWO4/B2O3 nanocomposite film improved to 0.07218 cm2/g compared to 0.06162 cm2/g for pure LDPE/SBR blend. However, a gradual increase was observed in both parameters of mean free path (MFP) and half value layer (HVL) as energy increases. Moreover, using Phy-X/PSD software, the experimental and theoretical data for MAC were compared. The dependency of the nanocomposite's effective atomic and electron numbers on BaWO4/B2O3 content was investigated. The fast neutron removal cross-section (ΣR) values were increased from 0.1081 to 0.2112 cm−1 as the BaWO4/B2O3 content increased to 20 wt%. Overall, these nanocomposite films are suitable for radiation shielding applications.

Universality of charge doping driven metal-insulator transition in Sr2RhO4 and role of spin-orbit coupling

We performed angle-resolved photoemission spectroscopy (ARPES) experiments on an electron-doped ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$ system ${\mathrm{Sr}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{RhO}}_{4}$ in order to investigate the electron doping-induced metal-insulator transition (MIT). We establish the universality of MIT in electron-doped ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$ by comparing results from ${\mathrm{Sr}}_{2\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{RhO}}_{4}$ and ${\mathrm{Sr}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{RhO}}_{4}$. Via a systematic analysis of doping-dependent transport and ARPES data, we show that the correlation driven MIT with a noninteger electron number in electron-doped ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$ is universal and thus independent of the dopant. Within the universality, the ARPES analysis shows that the band topology determined by the spin-orbit coupling (SOC) is likely a control parameter of the insulating gap size and critical electron number of the MIT. We present a phase diagram of the insulating phase as a function of the effective SOC and electron number.

Thermoelectric properties and low-temperature transport anomalies in the p -type full-Heusler compounds Fe2−xCrxVAl

Elemental substitutions are successfully used for the optimization of thermoelectric properties of a specific material; it requires, however, a deep understanding of its impact. For this purpose, based on the full-Heusler material ${\mathrm{Fe}}_{2}\mathrm{VAl}$, various compounds (${\mathrm{Fe}}_{2\ensuremath{-}x}{\mathrm{Cr}}_{x}\mathrm{VAl}$) were synthesized by substituting Cr for Fe in a wide range from $x$ = 0.005 up to $x$ = 0.4. X-ray diffraction analysis revealed full solubility of Cr for all concentrations. Bulk thermoelectric properties, such as electrical resistivity, Seebeck coefficient, thermal conductivity, and Hall resistivity were measured from 2 K up to 780 K, and all results were discussed in the context of the outcome of density functional calculations. Transport anomalies, resembling Kondo scattering, were observed for all samples below 30 K. Finally, an increased effective number of valence electrons of 7 for Cr was phenomenologically determined, which revealed good agreement with other $p$-type doping studies of ${\mathrm{Fe}}_{2}\mathrm{VAl}$.

Cole-Cole analysis and optoelectronic properties, using VEELS, of KNNS ferroelectric ceramics

In this work, Cole-Cole analysis and optoelectronic properties were carried out on K 0.1 Na 0.9 Nb 0.97 Sb 0.03 O 3 (KNNS) ferroelectric ceramics with tetragonal phase. Moreover, some evidence of the 180° domains, relating the electronic interband transitions (J cv ) and the Cole-Cole plot obtained from the complex dielectric function constants. Both obtained by Kramers-Krӧnig analysis. The experimental method enabled monitoring the materials properties of the material between inter-bands transitions and plasmons. Concerning the optical reflection coefficient observed from KNNS, the observed values of reflection coefficients were about 15% for an energy loss of 0 eV and a peak value at about 32% at 5 eV, followed by a second peak equivalent to 18% at 11 eV. The number of effective electrons (n eff ) participating in the inter-band transitions of the KNNS material is relevant up to 40 eV. These results suggest that KNNS could be a material to enable terahertz waveguide, enabling a new generation of high-speed communications devices. • Cole-Cole analysis and optoelectronic properties were carried out on KNNS (K0.1Na0.9Nb0.97Sb0.03O3) • Ferroelectrics 180° domains is identified by HRTEM. • Electronic Interband transitions J cv and the Cole-Cole plot obtained from the dielectric function. • The number of effective electrons (neff) in the inter-band transitions of the material is up to 40 eV. • These results suggest that KNNS could be a material for terahertz waveguiding.

Shielding Properties of Glass Samples Containing Li2O, K2O, Na2O, PbO and B2O3 by Geant4, XCOM and Experimental Data

Abstract: In the present work, glass samples containing 10Li2O, 10K2O, 20Na2O. xPbO, (60-x)B2O3 (where x = 0-60) were prepared by the melt quenching method. The shielding parameters of the prepared samples were measured experimentally and calculated theoretically. The measurements have been performed at energies of 356.5, 662, 1173 and 1333 keV to obtain the total mass attenuation coefficient (μm), using a gamma spectrometer containing a shielded NaI (TI) detector. The results of mass attenuation coefficient (μm), half-value layers (HVLs), mean free path (MFP), radiation protection efficiency (RPE), atomic and electronic electron cross-sections (σa and σe), effective atomic number (Zeff) and effective electron number (Neff) were calculated at energies from 1 keV to 100 GeV using the Monte Carlo simulation code Geant4 and XCOM. The calculated results were compared with each other and with the experimental values. Good agreement has been observed. Keywords: Shielding properties, Glass, Photon mass attenuation coefficient, Atomic and electronic cross-sections, Effective atomic and electron numbers, XCOM, Geant4.

Remark on the correlation between the refractive index and the optical band gap in some crystalline solids

The correlation between static refractive index (ns) and optical band gap (Eg) based on the Wemple-DiDomenico (WD) model and the empirical correlation between the energy of an effective dispersive oscillator and optical band gap is examined for 52 crystalline solids. A comparison with two recently published empirical relationships between ns and Eg indicates that the use of the WD model provides better results and, more importantly, connects the ns versus Eg dependence with some chemical characteristics of solids such as the coordination number of cation, the valence of anion, the effective number of valence electrons and ionicity.

Numerical Investigation on Photon Sensing Parameters for Some Thermoluminescence Dosimeters: A Comparative Study

In the present work, twelve inorganic thermoluminescence dosimeteric (TLD) materials doped with some rare earth elements (LiF:Sm, LiBaP2O7:Eu, CaCO3:Eu, CaSO4:Dy, SrSO4:Sm, CdSO4:Dy, BaSO4:Eu, Li2B4O7:Dy, MgB4O7:Gd, Al2O3:Gd, MgAl2O4:Ce and LiCaAlF6:Eu) and three organic TLD materials (C3H7NO2, C7H8O2 and C4H6BaO4) were selected for comparative analysis on the basis of different photon sensing parameters. About nine photon sensing parameters viz. mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), mean free path (mfp), half value layer (HVL), tenth value layer (TVL), effective atomic number (EAN), effective electron number (EEN), exposure buildup factor (EBF) and energy absorption buildup factor (EABF) were obtained for the selected fifteen TLDs. The simultaneous variation of these photon sensing parameters for the selected TLDs with photon energy and composition has been analyzed. The results of present comparative analysis help radiation physicists to easily select a particular dosimeter for their research laboratory from different existing compositions. All photon sensing parameters viz. MAC, LAC, mfp, HVL, TVL, EAN, EEN, EBF and EABF for selected TLDs strongly depend upon incident energy and chemical composition in lower and higher energy regions. Among the selected TLDs; BaSO4: Eu3+ offers best results (maximum values for MAC, EAN, EEN; and minimum values for mfp, HVL, TVL, EBF, EABF); whereas MgB4O7:Gd3+ offers EAN value close to tissue and less variation in most of the sensing parameters with respect to photon energy.

Transport properties for neutral C, H, N, O, and Si-containing species and mixtures from the Gordon and McBride thermodynamic database

Accurate transport properties of non-ionized gas mixtures of C, H, O, N, and Si-containing species at temperatures up to 4000 K are essential in many scientific fields. Mixture transport properties are computed through the solution of linear transport systems, requiring collision integrals as functions of temperature for each binary collision pair in the mixture. Due to the dimensionality of the problem, no such database exists for all the 180 hydrocarbons and silicon species detailed in the nine-coefficient polynomial thermodynamic database of Gordon and McBride, widely used in many applications. This constraint was overcome by using a phenomenological inter-molecular potential energy surface suitable for transport properties, which describes the pair interaction approximated with two fundamental species physical properties, namely the dipole electric polarizability and the number of effective electrons participating in the interaction. These two parameters were calculated with ab initio quantum chemistry calculations, since they were not always available in literature. The studied methodology was verified and validated against other approaches at a species and collision integral level. Transport properties for a variety of equilibrium mixtures, including planetary atmospheres and chemical compositions of thermal protection materials relevant to aerospace applications, were calculated, assessing the predictive capabilities of this new database.

DETERMINATION OF RADIATION SHIELDING PARAMETERS OF COCRFENITIALX ALLOYS BY USING RECENTLY DEVELOPED PHY-X/PSD AND EPIXS SOFTWARES

We calculate the radiation shielding parameters of CoCrFeNiTiAlx alloys which consist of mass attenuation coefficient, linear attenuation coefficient, mean free path, half-value layer, total atomic cross section, effective atomic number and effective electron number. For this, we use recently developed Phy-X/PSD and EpiXS softwares. We compare all the results with each other, and discuss the relationship between the results.

Unified treatment for photoluminescence and scattering of coupled metallic multi-nanostructures

We present a multimer coupling classic harmonic oscillator model to reveal the scattering and photoluminescence (PL) properties of metallic nanoparticle chains. Taking particle number from 1 to 6 as examples, we compare the calculated spectra with the experimental ones from other researchers’ work, and they agree well with each other. Furthermore, scattering and PL properties are analyzed carefully varying with particle number n, coupling strength g, and effective free electron number N. Results indicates larger red-shift and smaller full width at half maximum (FWHM) of the scattering spectra with larger n or/and larger g. Particularly, the limitation of the red-shift is obtained in the limit of n→∞. Meanwhile, the splitting of PL modes increases as g increases, and the amplitudes are dependent on the excitation wavelength. This classic model is simple and shows a unified treatment for understanding the scattering and PL properties of multimer coupled systems.

Structural and shielding properties of the tellurite-tungsten glass matrix with addition zinc fluoride

In this study, we reported the radiation protection characteristics of TeO2-WO3-ZnF2 glass systems with different compositions. The composition of the glasses are (0.8 - x) TeO2– 0.2WO3–xZnF2, 0.7TeO2-0.1WO3-0.2-ZnF2 and 0.6TeO2-0.15WO3-0.25ZnF2 (where x = 0.1,0.2,0.3). The radiation shielding parameters including mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half value layer (HVL), mean free path (MFP), tenth value layer (TVL), effective atomic number (Zeff), effective electron number (Neff), and atomic and electronic cross sections (ACS and ECS) have been determined for the prepared glasses against a broad range of ionizing energy between 0.015 and 15 MeV. The structure of the prepared glasses was investigated by using Raman spectra. It obtained that, the incorporation of WO3 into the TeO2 glass network causes the creation of W–O–W connections, while Te–O–W linkages with greater electronic polarizability improve the glass network's connectedness. The study demonstrates that the TeO2-WO3- ZnF2 glass system can be utilized for radiation protection against ionizing radiation in a variety of medical and technical applications.

Correlation of physical parameters features with optical and radiation shielding properties of heavy glass

In this paper we discussed the optical and radiation shielding properties are strongly dependent on the physical parameter viz; (i) interionic interaction parameter, A(n0), (ii) coordination number, CN, (iii) single bond strength (BM-O) and (iv) optical basicity, Λ(n0) of glasses (95-x) TeO2– 5Ta2O5 -xBi2O3) where x = 5, 10, 15, and 20 in mol %. Furthermore, the various optical parameters viz; linear refractive index, optical absorption coefficient, optical energy gap, Urbach energy, density, oxygen molar volume, nonlinear refractive index, molar refraction, oxygen packing density, reflection loss, molar electronic polarizability of fabricated glasses were estimated. The shielding parameters viz; mass attenuation coefficient, linear attenuation coefficient, half value layer, mean free path, tenth value layer, effective electron number, effective atomic number, atomic and electronic cross sections have been calculated of fabricated glass against a wide range of ionizing energy ranging from 0.015 to 15 MeV. Results showed that increasing the concentration of Bi2O5 from 5 to 20% led to an increase in the linear attenuation coefficient (LAC). Compared with commercially available standards and reported some tellurite glasses to contain Bi2O3 in the literature, the investigated material showed superior performance at energies ranging between 800 keV and 10 MeV. Radiation protection efficiency (PRE) of 70TeO2–5Ta2O5–20Bi2O3 glass varied from 99.9 to 83.9% at low energy from 15 to 200 KeV. Therefore, this glass has a high density, refractive index, and a superior capability of radiation shielding materials at low energy.

Thermal Stability, Optical Properties, and Gamma Shielding Properties of Tellurite Glass Modified with Potassium Chloride.

The synthesized glass system with a composition of (80-x) TeO2-10P2O5-10Nb2O5-xKCl mol% (where x = 5, 10, 15, 20, and 25) was successfully fabricated. The density (ρ) and molar volume (Vm) have been calculated. The investigated glasses were characterized using different analysis methods (differential thermal analysis (DTA) and UV-VIS-NIR spectroscopy). The radiation shielding effectiveness of the synthesized glass system was evaluated using different shielding parameters, such as mass and linear attenuation coefficients (MAC, LAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and effective electron number (Neff). The results showed that with the increasing potassium chloride (KCl) concentration and decreasing tellurium oxide (TeO2) concentration, the density, refractive index, Urbach energy (Eu), and glass transition temperature (Tg) decreased, while the optical energy gap (Eopt) and thermal stability increased. As the KCl concentration increases, the values of MAC, LAC, and Zeff increase in the following order: TPNK5 % > TPNK10 % > TPNK15 % > TPNK20 % > TPNK25 %. Additionally, the shielding effectiveness of TPNK glass system showed good performance compared with some standard materials. The synthesized glass with a minimum KCl content has both good shielding effectiveness and good optical properties, in addition to reasonable thermal stability, which makes it suitable for shielding and optical applications.