Photon Energy Range Research Articles

Unveiling the pressure-induced physical variations in Cs2SnBr6 and Cs2SnCl6: A DFT study

This study employs the FP-LAPW method based on DFT to investigate the structural, electronic, and optical properties of Cs2SnBr6 and Cs2SnCl6 under a range of pressures up to 30[Formula: see text]GPa. We use the TB-mBJ functional to analyze the electronic and optical properties of the materials, while the GGA–PBEsol is employed to study their structural properties. Applying pressure causes a decrease in the unit cell volume and lattice constant of the double perovskites. At zero pressure, both Cs2SnBr6 and Cs2SnCl6 exhibit a direct bandgap. The bandgaps of both the materials decrease as the pressure increases from 0[Formula: see text]GPa to 20[Formula: see text]GPa but slightly increase for the increase in pressure from 20[Formula: see text]GPa to 30[Formula: see text]GPa. The DOS analysis conducted at 0[Formula: see text]GPa and 30[Formula: see text]GPa demonstrates a decrease in the number of states per[Formula: see text]eV as the pressure increases, along with an increase in bandwidth and a shift of the peaks toward negative energy. The electron density contours exhibit the presence of both covalent and ionic bonds at zero pressure, whereas at a pressure of 30[Formula: see text]GPa, the covalent bond strength is enhanced. Optical properties of Cs2SnBr6 and Cs2SnCl6 were investigated over a pressure range of 0–30[Formula: see text]GPa and a photon energy range of 0–10[Formula: see text]eV. With increasing pressure, the initial peak in these parameters was red-shifted due to a decrease in bandgap energy, while the remaining peaks blue-shifted due to the broadening of conduction and valence bands.

A DFT-based computational study on a highly and lead-free inorganic new fluoroperovskite of Mg3PF3

Inorganic fluoroperovskite materials are increasingly important in solar technology due to their exceptional structural, optical, electronic, and mechanical properties. This study uses DFT calculations to investigate the properties of Mg3PF3 fluoroperovskite. Our results show a crystal structure and lattice parameter of (a = 4.64 Å) which align with previous theoretical and experimental findings, confirming the accuracy of our calculations. Mechanical analysis reveals that Mg3PF3 is naturally ductile, elastically anisotropic, and stable according to established criteria. The band structure and PDOS indicate that it is a semiconductor with direct bandgap of 3.88 eV at the Γ point, making it suitable for electronic applications. Electron charge density mapping suggests a predominantly ionic bonding nature. Optical property analysis shows significant dielectric constant peaks in the photon energy range favorable for solar cells. Overall, these findings position Mg3PF3 as a promising candidate for solar cell technology, highlighting its potential for enhancing renewable energy solutions.

Comparison of X-Ray Absorption in Mandibular Tissues and Tissue-Equivalent Polymeric Materials Using PHITS Monte Carlo Simulations

This study investigates the absorption of X-rays in mandibular tissues by comparing real tissues with tissue-equivalent materials using the PHITS Monte Carlo simulation program. The simulation was conducted over a range of X-ray photon energies from 50 to 100 keV, with increments of 5 keV, to evaluate the dose absorbed by different tissues. Real tissues, such as the skin, parotid gland, and masseter muscle, were compared with their tissue-equivalent polymeric materials, including PMMA, Parylene N, and Teflon. The results showed that the real tissues generally absorbed more X-rays than their corresponding equivalents, especially at lower energy levels. For instance, at 50 keV, differences in the absorbed doses reached up to 50% for the masseter muscle and its equivalent, while this gap narrowed at higher energies. The study highlights the limitations of current tissue-equivalent materials in accurately simulating real tissue behavior, particularly in low-energy X-ray applications. These discrepancies suggest that utilizing tissue-equivalent materials may lead to less accurate medical imaging and radiotherapy dose calculations. Future research should focus on improving tissue-equivalent materials and validating simulation results with experimental data to ensure more reliable dosimetric outcomes. This study provides a foundation for refining radiation dose calculations and improving patient safety in clinical applications involving X-rays.

On the valence shell spectroscopy of 1,2-dichlorobenzene

We report high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of 1,2-dichlorobenzene in the photon energy range 4.0–10.8 eV (310–115 nm). The electronic state spectroscopy of ortho-C6H4Cl2 has been investigated together with quantum chemical calculations at different levels of theory, also providing vertical excitation energies and oscillator strengths. The valence, mixed valence-Rydberg and Rydberg character of the electronic transitions is accompanied by fine structure which has been mainly assigned to in-plane breathing with C–Cl stretching, v7′a1, ring breathing and C–C stretching, v8′a1, in-plane ring breathing, v9′a1, C–Cl symmetric stretching, v10′a1, and in-plane C–Cl bending v11′a1 modes. The experimental absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of 1,2-dichlorobenzene in the Earth’s atmosphere (0–50 km), showing that solar photolysis is expected to be a weak sink at altitudes lower than 20 km relative to OH radical reactions. Potential energy curves for the lowest-lying excited electronic states, as a function of the C–Cl stretching and in-plane C–Cl bending coordinates, were also obtained employing the time dependent density functional theory (TD-DFT) method. The results show the importance of the complex quasi-degenerate nature of the lowest-lying electronic states which in the intricate nuclear dynamics of the reaction coordinates, yield relevant internal conversion from Rydberg to valence character and in the asymptotic limit bond excision.

A Novel Anthropometric Phantom for Rapid Radiological Triage: A Quick Sort Triage Solution.

Rapidly identifying individuals who have received internal radiation exposure above action guidelines is crucial for mitigating health risks and addressing public concerns immediately following a radiological event involving the dispersal of radioactive materials. This study describes a novel triage method using a conventional Geiger-Mueller (GM) detector to select those individuals from the large group of persons who may have received an intake of radioactive material at levels corresponding to one Clinical Decision Guide (CDG). The triage method involves placing a portable GM detector against the lower anterior torso of a sitting person as they bend over to surround the detector with their body. The response of the GM detector is evaluated using a new, specially designed anthropometric phantom that simulates combined tissues of the lower thorax and gastrointestinal (GI) tract and is fabricated with a tissue substitute material that matches the overall radiological properties of human tissue present in this body region. The phantom has four separate layers of tissue substitute material with ports to accommodate a single GM detector at the center and one or more sealed radioactive sources that can be arranged to characterize the detector response for a variety of source distributions, including a "hot spot." In this study, the response of a Ludlum Model 133-4 GM detector was evaluated using sealed sources of 232Th and 137Cs to determine the measurement efficiency for a quantity of activity present in the abdomen within a few hours post-intake equivalent to 1 CDG. Results demonstrate that the Quick Sort triage procedure using a single GM detector placed against the abdomen of a person can reliably detect internal deposition resulting from an intake equivalent to 1 CDG for 232Th or a significantly lower activity of 137Cs within a few hours following a radiological incident. The evaluation was performed over a wide range of photon energies, so the Quick Sort triage procedure is expected to be suitable for most fission products distributed uniformly within the abdomen or as a single "hot spot."

Interaction Parameters of Some Polymers Used in Nuclear Power Plants with Ionizing Radiation, Produced Secondary Radiations and Radiation Damages

AbstractThe primary interactions of polypropylene (PP), poly(vinyl acetate) (PVA), ethylene‐vinyl acetate (EVA), polyvinyl chloride (PVC), polychloroprene (CR) and polyurethane (PUR) polymers preferred in the nuclear industry with gamma and neutron radiations, secondary radiations formed after neutron interactions and damages given to polymers by these ionizing radiations are investigated. The gamma interaction parameters Were determined in the photon energy range of 0.03‐20 MeV using WinXCOM, GEANT4 and FLUKA methods. Also, energy absorption and exposure buildup factors and Kerma parameters are calculated at different photon energies. To investigate the interactions of the studied polymers with neutron, the effective removal cross‐section for fast neutrons with theoretical and the partial neutron rates passing through the studied polymer at 4.5 MeV, 100 eV and 0.025 eV energies are determined with simulation codes. The numbers of secondary gamma‐rays and neutrons Were obtained with GEANT4. The Total Ionizing Dose and Displacements per Atom parameters are studied with the help of FLUKA simulation. It is observed that the interaction of PVC polymer with gamma radiation and PP polymer with neutron particles is higher than the others. The secondary radiation from PVC and CR is less. The PP, PVA, and EVA exhibit superior resistance to radiation damage.

Strain effect on the physical properties of novel Mg3NI3 perovskite material: First principle DFT analysis

Inorganic perovskite-based substances have become a major attraction to solar technology. Inorganic cubic Mg3NI3 perovskites have generated a heap of fascination owing to their distinctive optical, electrical, and structural features. The photovoltaic and optoelectronic industries prioritize lead-free, atomically tailored metal halide perovskites due to the need to address lead (Pb) toxicity and instability. This study assessed the optical, structural, and electrical parameters of Pb-free inorganic halide perovskites Mg3NI3 as a function of biaxial compressive and tensile strain, leveraging first-principles density-functional theory (FP-DFT). Refractive index, absorption coefficient, reflectivity, dielectric function, and tolerance factor are a few additional optical parameters that are computed and processed. The bandgap of the planar Mg3NI3 molecule is 0.412 eV (PBE) when SOC is not applied. The bandgap reduces to 0.363 eV (PBE) at its Γ(gamma) and R-point when the subjective SOC effect is taken into consideration. This compound's bandgap will narrow under tensile strain and expand under compressive strain, depending on whether the SOC effect is applied or not. Several elastic factors are anticipated, including the bulk modulus, Pugh's ratio, elastic constants, anisotropic factors, and Poisson's ratio. Electronic property calculations using band mechanism and density of states (DOS) suggest that Mg3NI3 have a bandgap that is indirect and semiconductive. The elastic properties of this material were found to be mechanically stable, anisotropic, and ductile. In the photon energy range suitable for solar cells, the spikes in the dielectric constant of Mg3NI3 are seen. Our findings point to the prospect of Mg3NI3 as a non-toxic, high-performance, low-cost material for implementation in solar cells and different semiconductor devices.

Manganese diluted TlInS2 layered semiconductor: Optical, electronic and magnetic properties

Manganese–doped TlInS2 (TlInS2+Mn) layered semiconductors with different doping concentrations of about 0.1 and 0.3 at. percent were investigated. Photo–induced current transient spectroscopy (PICTS) measurements in the temperature range of 80 and 300 K have been made for identifying energy levels related to Mn dopant within the electronic bandgap of TlInS2+Mn crystal. Optical absorption spectra in the photon energy range of ∼1.8–3.1 eV have been extracted by fitting the transmittance spectra of TlInS2+Mn recorded at the temperatures varied from ∼40–300 K. A redshift trend of the absorption edge with increasing of temperature was observed. On the other hand, a blue shift in the absorption edge with Mn doping was observed in the absorption spectra. The Mn dopant induced photoluminescence (PL) was also investigated in the visible region ranging from 320 to 960 nm. Seven peaks were observed in the PL spectra of Mn doped TlInS2 crystal in the regions both ∼960–620 nm (∼1.3–2 eV) and ∼620–320 nm (∼2–3.8 eV) due to the electronic states of Mn ions. Laser–induced breakdown spectroscopy (LIBS) technique was applied to establish of the elemental chemical composition and to confirm presence of each constituent element in TlInS2:Mn. The dc magnetization measurements of TlInS2+Mn performed in a wide temperature range of ∼5 and ∼300 K revealed different (diamagnetic and paramagnetic states) magnetic phases inside the studied temperature range. The X–band electron paramagnetic resonance (ESR) experiments were carried out in the low–temperature phase of TlInS2+Mn to probe the structure of Mn centers in TlInS2. The measurements revealed that the ESR spectrum changes drastically in the low–temperature phase of TlInS2+Mn bulk sample. Finally, a detailed density functional theory (DFT) based computational investigation of electronic band structures, density of states and optical properties of TlInS2+Mn compound has been performed. The results of ab–initio calculations are discussed for three possible states when the manganese atom was doped by replacing either the Tl, In or S atoms in the unit cell of TlInS2. Additionally, the effect of interstitial Mn dopant on the electronic structure and optical properties of TlInS2 material has been simulated.

Relative biological effectiveness of clinically relevant photon energies for the survival of human colorectal, cervical, and prostate cancer cell lines

Objective.Relative biological effectiveness (RBE) differs between radiation qualities. However, an RBE of 1.0 has been established for photons regardless of the wide range of photon energies used clinically, the lack of reproducibility in radiobiological studies, and outdated reference energies used in the experimental literature. Moreover, due to intrinsic radiosensitivity, different cancer types have different responses to radiation. This study aimed to characterize the RBE of clinically relevant high and low photon energiesin vitrofor three human cancer cell lines: HCT116 (colon), HeLa (cervix), and PC3 (prostate).Approach.Experiments were conducted following dosimetry protocols provided by the American Association of Physicists in Medicine. Cells were irradiated with 6 MV x-rays, an192Ir brachytherapy source, 225 kVp and 50 kVp x-rays. Cell survival post-irradiation was assessed using the clonogenic assay. Survival fractions were fitted using the linear quadratic model, and survival curves were generated for RBE calculations.Main results.Cell killing was more efficient with decreasing photon energy. Using 225 kVp x-rays as the reference, the HCT116 RBESF0.1for 6 MV x-rays,192Ir, and 50 kVp x-rays were 0.89 ± 0.03, 0.95 ± 0.03, and 1.24 ± 0.04; the HeLa RBESF0.1were 0.95 ± 0.04, 0.97 ± 0.05, and 1.09 ± 0.03, and the PC3 RBESF0.1were 0.84 ± 0.01, 0.84 ± 0.01, and 1.13 ± 0.02, respectively. HeLa and PC3 cells had varying radiosensitivity when irradiated with 225 and 50 kVp x-rays.Significance.This difference supports the notion that RBE may not be 1.0 for all photons through experimental investigations that employed precise dosimetry. It highlights that different cancer types may not have identical responses to the same irradiation quality. Additionally, the RBE of clinically relevant photons was updated to the reference energy of 225 kVp x-rays.

Exploring the inorganic perovskite materials Mg3SbX3 (Where, X=I, Br, Cl and F) through the perspective of density functional theory: Adjustment of physical characteristics as consequence of strain

The solar technology industry has lately given inorganic perovskite materials an abundance of thought because of their unique optical, electrical and structural characteristics. Issues pertaining to lead (Pb) toxicity and instability require being referred to promptly, making lead-free atomically designed metal halide perovskites of foremost importance to the photovoltaic and optoelectronic industries. Perovskites, a class of inorganic metal halide semiconductors, have variant similarities with Mg3SbX3 (X = I, Br, Cl and F). According to the space group Pm-3m Mg3SbX3 (X = I, Br, Cl and F) has a cubic perovskite crystal structure. Utilizing first-principles density-functional theory (FPDFT), The intention of this investigation is to analyze how strain and spin-orbit coupling (SOC) impact the structural, electrical, optical and mechanical features of the inorganic cubic perovskite of Mg3SbX3 (X = I, Br, Cl and F). At the point between R and Γ, the Mg3SbI3,Mg3SbBr3,Mg3SbCl3 molecule displays an indirect bandgap of 0.105 eV, 0.957 eV, 1.728 eV. At the Γ point, the Mg3SbF3 molecule displays a direct bandgap of 3.184 eV. The bandgaps of the Mg3SbI3,Mg3SbBr3,Mg3SbCl3 and Mg3SbF3 perovskites are 0.198 eV, 1.203 eV, 1.901 eV and 3.723 eV respectively, when considering the spin-orbital coupling (SOC) quantum influence. A wider bandgap is investigated for increasing compressive strain while a smaller bandgap is observed for increasing tensile strain. Apart from the elastic constants and anisotropic factors, other factors that are anticipated include Pugh's ratio, Poisson's ratio, bulk modulus and others. Isotropic, ductile and mechanically stable are the words that best describe these materials, according to the elastic property evaluations. In the photon energy range that is appropriate for solar cells, the dielectric constant spikes of Mg3SbX3 are found to be visible. Therefore, Mg3SbX3 (X = I, Br, Cl and F) perovskite is a good material to use in solar cells for managing light and producing electricity.

On Theoretical Aspect of Photons Emission From Quark-Gluon Interaction Upon Hard Collision

Abstract This work applies a quantum chromodynamics theory QCD to photon emission from heavy quark-gluon scattering in the strong interaction quark-gluon to study and calculate photon flow in hard interaction processes. The photon flow from the dense quark-gluon interaction was calculated using critical temperature, quantum chromodynamic coupling and fugacity at chemical potential μq (500 MeV) for the anti-top with gluon interaction in t ¯ g → s ¯ γ system. The photon flow spectrum in hard collisions is described under the first leading order approximation for QCD theory at finite chemical potential and critical temperature using various photon energy values dependent on the fugacity of quark and gluon. Photon flux calculation provided valuable insights into QGP conditions. The coupling strength αc (T) calculation is a strongly decreasing function of critical temperature ranging 107MeV ≤ Tc ≤ 145MeV and also find appreciable increasing as a result of increasing temperature of system ranging 180MeV ≤ T ≤ 360MeV. The photon flow produced in the t ¯ g → s ¯ γ system was observed in the low range of photon energy with two critical temperatures. The total photon emission strongly decreases marginally as a function of the increase in photon energy. The photon flow emission was found to have appreciable enhancement at the anti-top quark interaction with gluon and it increases highly as a result of the increased temperature of the system and reaches to maximum near 360 MeV at minimum strength coupling in the energy of the photon 1GeV≤E≤2 GeV.

Orientation-resolved attosecond photoionization delays in the N2O molecule

We present a thorough theoretical and experimental investigation of photoionization time delays in the N2O molecule. Our theory provides actual XUV+IR time-resolved photoelectron spectra as measured in real reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) experiments. This requires not only accounting for the interaction between the XUV field and the neutral molecule, but also between the IR field and the ejected electron, which is only possible through explicit evaluation of a large number of dipole couplings between molecular electronic continuum states. To compare with the results of these calculations we have performed RABBIT experiments in which the ejected electron and the resulting ionic fragments are measured in coincidence, thus allowing us to obtain photoionization delays for a particular orientation of the molecule with respect to the polarization of the XUV and IR fields. We have found very good agreement between calculated and measured RABBIT spectra for both nondissociative and dissociative ionization channels. In particular, we unambiguously show a photoionization delay of about 60 as in the vicinity of a well-known shape resonance of N2O in the nondissociative ionization channel. More importantly, we show a dramatic effect of the IR field in the orientation-resolved ionization delays in the whole photon energy range investigated in this paper (18–40 eV), even at the level of ionization delays (i.e., delays referred to an internal reference delay) where the effect of the IR field is generally assumed to cancel out. Finally, we explicitly show that the problem of spectral congestion inherent to most molecular systems, which usually prevents extraction of photoionization delays, is substantially alleviated by resolving the molecular orientation or, ideally, by resolving both the molecular orientation and the electron emission angle, where access to perfectly isolated ionization channels is possible at specific angles. Published by the American Physical Society 2024

Experimental, simulation, and theoretical investigations of gamma and neutron shielding characteristics for reinforced with boron carbide and titanium oxide composites

This study investigates the radiation shielding properties of composites containing polyester resin, boron carbide and titanium oxide in varying proportions. The radiation transmittance of the produced composites was measured using radioactive sources 241Am, 137Cs, 133Ba, 60Co, and 22Na across a photon energy range of 59.5 keV–1332.5 keV. To analyze radiation permeability, experimental geometry was simulated using Monte Carlo-based computer codes Monte Carlo N-Particle (MCNP), Particle and Heavy Ion Transport code System (PHITS) and FLUktuierende KAskade or Fluctuating Cascade (FLUKA), and the experimental data were compared with simulation results and theoretical data obtained from WINXCOM. The findings demonstrated a high degree of consistency between experimental, simulation, and theoretical results. Notably, the BCTiO50 sample, which included a 50% addition of TiO2, emerged as the most effective in photon radiation shielding. In addition to gamma shielding, the neutron shielding properties of the produced composites were evaluated using the FLUKA code, revealing that the BCTiO0 sample, with the highest percentage of boron, provided the best neutron shielding. This analysis included composites with decreasing boron carbide content by 10%, 20%, 30%, 40%, and 50% by weight, each replaced with titanium oxide, showcasing the potential applications of these polymer composites in radiation shielding.

Yttria-doped geopolymers: Environmentally friendly and effective materials for shielding concrete in gamma radiation facilities

The use of geopolymer in place of ordinary Portland cement for concrete design and constructure is gaining attraction due to environmental and health considerations. Geopolymers must have high gamma radiation shielding competence in order for them to be useful for radiation shielding concrete. In an attempt to improve the gamma absorption capacity of a metakaolin-based geopolymer matrix, 10 % (GEO-10Y), and 20 % (G-20Y) yttria (Y2O3) was mixed with GEO through a solid-state reaction process. In this study, the influence of adding yttria on the physical and gamma shielding parameters of GEO was investigated. The densities of GEO, GEO-10Y and GEO-20Y were obtained as 2.28, 2.52 and 2.37 g/cm3, respectively. Through simulation using FLUKA code, the mass attenuation coefficients (MAC) and other relevant shielding quantities were estimated. The MACs of GEO, GEO-10Y, and GEO-20Y were within the range of 0.0213–6.6429 cm2/g, 0.0282–13.3923 cm2/g, and 0.0291–14.5136 cm2/g, respectively. The addition of yttria improved the gamma photon shielding competence of the metakaolin-based geopolymer by increasing the MAC and reducing photon buildup factors within 15 keV–15 MeV photon energy range. The shielding effectiveness of the yttria-doped GEO compares well with conventional shielding materials. Yttria-doped geopolymer can be used to produce effective and environmentally-friendly gamma shielding concrete.

Simulation and calculation of the radiation attenuation parameters of newly developed bismuth boro-tellurite glass system

This paper presents a comprehensive simulation and calculation study of the radiation attenuation parameters for a newly developed bismuth boro tellurite glass system. Through advanced computational modeling and theoretical analysis, linear and mass attenuation coefficients (μ and μ/ρ), and other key radiation attenuation parameters of the studied glass system are thoroughly investigated across a range of photon energies. Utilizing state-of-the-art simulation techniques and theoretical models, the radiation shielding effectiveness of the glass system is evaluated, offering insights into its potential applications in radiation protection and shielding. We found that the ΣR values for fast neutrons are 0.10013, 0.10221, 0.10953, 0.11347 and 0.11383 cm−1 for BTBiBV-1, BTBiBV-2, BTBiBV-3, BTBiBV-4, and BTBiBV-5, respectively. The results of this study contribute to the understanding of the radiation attenuation properties of bismuth boro tellurite glasses and provide valuable information for their utilization in various fields, including medical imaging, nuclear power, and industrial radiography. Additionally, accurate modeling and characterization of attenuation parameters across different photon energies are crucial for designing effective radiation protection strategies and ensuring the safety of personnel and equipment in radiation environments.

Optical design of the time-resolved ARPES beamline of the new material spectroscopy experimental station for the update of CAEP THz-FEL facility

Abstract The Chinese Academy of Engineering Physics Terahertz Free Electron Laser Facility (CAEP THz FEL, CTFEL) is the only high-average power free electron laser terahertz source based on superconducting accelerators in China. The update of the CTFEL is now undergoing and will expand the frequency range from 0.1-4.2 THz to 0.1-125 THz. Two experimental stations for material spectroscopy and biomedicine will be built. A high harmonic generation (HHG) lightsource based beamline at the material spectroscopy experimental station for time-resolved angle-resolved photoemission spectroscopy (ARPES) research will be constructed and the optical design is presented. The HHG lightsource covers the extreme ultraviolet (XUV) photon energy range of 20-50 eV. A Czerny-Turner monochromator with two plane gratings worked in conical diffraction configuration is employed for maintaining the transmission efficiency and preserving the pulse time duration. The calculated beamline transmission efficiency is better than 5% in the whole photon energy range. To our knowledge, this is the first time in China to combine THz-infrared FEL with HHG light source, and this experimental station will be a powerful and effective instrument and give new research opportunities in the future for users doing research on dynamic evolution of excited electron band structure of material surface.

An ab initio analysis of the electronic, optical, and thermoelectric characteristics of the Zintl phase CsGaSb2

We present and analyze the findings of a comprehensive ab initio computation that examines the electronic, optical, and thermoelectric characteristics of a recently synthesized Zintl compound known as CsGaSb2. The electronic and optical characteristics were examined using the DFT-based FP-L/APW+loapproach. Toaddress the exchange–correlation effects, we employed the GGA-PBEsol and TB-mBJ approaches.The CsGaSb2 semiconductor exhibits an indirect bandgap of 0.695 eV when analyzed with the GGA-PBEsol approach, and a bandgap of 1.254 eV when analyzed with the TB-mBJ approach.The PDOS diagrams were used to discover the origins of the electronic states that make up the energy bands. The charge density study reveals that the Ga-Sb link within the [GaSb2] block is mostly governed by a covalent character, whereas the cation Cs+ and polyanion [MSb2]−bonding is predominantly ionic. The frequency dependence of macroscopic linear optical coefficients was evaluated over a broad range of photon energies from 0 to 25 eV. The thermoelectric characteristics were investigated via the Boltzmann kinetic transport theoryassuming a constant relaxation time.The compound’s figure of merit at a temperature of 900 K is roughly 0.8.

Investigation of thermodynamical stability and generation of large half-metallic gap along with optical properties in N-doped YHfO3 (YHO) (Y = Ca, Sr, and Ba) perovskite materials by first principle calculations

Considerable energy gap (Eg) in insulating channel, high spin-filtering, significant mean free path, and high magnetic transition temperature (TC) escalate half-metallic (HM) ferromagnetic (FM) materials very enticing for spintronic applications. Herein, ab-initio calculations have been executed comprehensively to inquest the structural, thermodynamical, electronic, magnetic, and optical properties of pure as well as nitrogen (N)-doped YHfO3 (YHO) (Y = Ca/Sr/Ba) materials with one N atom added at one of the oxygen (O) site. First, the thermodynamical stability of both bulk and doped YHO systems has been examined by estimating the formation enthalpies (ΔHf) by Convex Hull analysis, which confirms the practical realization of these materials on experimental grounds. Moreover, mechanical stability of these systems is affirmed by estimating the necessary elastic constants and respective parameters. Strikingly, all doped systems possess complete (100%) splitting in spin↑ and spin↓ channels at Fermi level and depict HM FM character with significant Eg of 3.31, 3.49, and 3.24 eV in spin↓ channels for CaHO (CHO), SrHO (SHO), and BaHO (BHO) systems, respectively. It is also found that N 2p orbitals are totally responsible for the emergence of metatallicity and magnetic character in all these doped structures. Moreover, the ground state long range FM stability between two added N atoms in doped systems is affirmed by computing the difference of total energies of FM and anti-ferromagnetic (AFM) spin ordering (ΔE) along with estimated TC at different distances. Lastly, it is found that N-doped systems have a lower optical energy loss than pristine YHO systems in the incident photon energy range of 0-50 eV. Hence, the present study proposes that an unconventional doping approach with intrinsically non-magnetic element in a variety of YHO perovskite systems could be a useful method to alter their various physical properties and forecast their potential applications in the development of novel spintronic and optoelectronic devices.

Effect of Phytic Acid, Tin Oxide and Graphite Incorporation in Polyaniline Semiconductive Ink

Enhanced electrical conductivity and pressure sensing functionalities of phytic acid-doped polyaniline ink (PPhyA) incorporated with SnO2 (PPhyAS) and graphite flakes (PPhyAG) as reported in our previous article, encouraged us to explore the electrical conduction mechanism and associated optical properties. In order to realize the enhanced electrical conduction in the reported inks, detailed studies were carried out in our research described here in comparison with normal HCl-doped polyaniline (PANI). This can be attributed to the formation of a highly ordered molecular arrangement with high crystallinity, a change in the hopping pathway between two adjacent molecules and the hopping activation energy of the PANI chain in the phytic acid-doped ink systems. Optical parameters, such as absorption edge, Urbach energy, refractive index, extinction coefficient, optical conductivity and optical dielectric constants, were estimated from the result of UV-Vis spectroscopy. The results of these studies showed enhancement of the optical properties of the phytic acid-doped ink systems (PPhyA, PPhyAS and PPhyAG) in the low photon energy range as compared to HCl-doped PANI. Phytic acid-doped ink systems are paintable on a variety of flexible surfaces, such as paper and plastics. Hence, we suggest that the phytic acid-doped ink systems have a great potential for developing flexible and foldable circuitry for infrared optics and remote sensing.

Beam Effects in Synchrotron Radiation Based Operando Characterization of Battery Materials: XRD and XAS Study of LiNi0.33Mn0.33Co0.33O2 and LiFePO4 Electrodes

Operando synchrotron radiation-based characterization techniques applied to energy storage materials are becoming a widespread characterization tool as they allow for non-destructive probing of materials with various depth sensitivities through spectroscopy, scattering, and imaging techniques. Moreover, they allow for faster acquisition rates, variable penetration depths, higher spectral or spatial resolution, or access to techniques that are only possible with a continuous tuneable source over a wide photon energy range. Compatibility between the electrochemical cell designs and the experimental setups may force some specific design features and care must be taken to ensure that these do not perturb the electrochemical response of the materials under investigation. The use of operando techniques has intrinsic advantages, as they enable the detection of metastable intermediates, if any, and ensure characterization under real conditions avoiding the risk of ex situ sample evolution during its preparation. However, they do not come with the extent of risks. The interaction between synchrotron radiation and samples, particularly within the intricate milieu of an operational electrochemical cell, can induce unexpected effects in the sample at the measurement spot, thereby jeopardizing the experiment's reliability and biasing data interpretation. While beam-induced effects are well-recognized for their critical impact on characterizing biological samples, macromolecules, or soft matter, they have, until recently, received scant attention within the battery research community, being vaguely referenced and incompletely understood. With the aim of contributing to this ongoing debate, a systematic investigation into these phenomena was carried out conducting a root cause analysis of beam-induced effects during the operando characterization of two commercially employed positive electrode materials: LiNi0.33Mn0.33Co0.33O2 and LiFePO4. The study spans across diverse experimental conditions involving various cell types, absorption and scattering techniques and seeks to correlate beam effects with factors such as radiation energy, photon flux, exposure time, and other parameters associated with radiation dosage. As a conclusion, a set of guidelines and recommendations are provided to evaluate and mitigate beam-induced effects that can affect the outcome of battery operando experiments.