Polarization Properties Research Articles

Induced polarization of clay-rich materials — Part 5: Influence of hyperalkalinity in bentonites

A total of 54 new core samples were built by mixing smectite-rich MX80-bentonite and Fontainebleau (silica) sand to study the effect of a hyperalkaline pore solution (including the presence of potassium) on the induced polarization properties of these mixtures. Two types of experiments were performed. In the first set of experiments, we performed induced polarization measurements 10 minutes after the preparation of the core samples (static experiments) for a broad variety of water contents and saturations. The second set of experiments was performed for over 1000 hours to study the potential effect of illitization upon the induced polarization properties (time-lapse experiments). Indeed, in the presence of potassium in the hyperalkaline pore solution favors the transformation of smectite into illite. Furthermore, we expect cation replacement (sodium replaced by calcium and potassium) in the smectite interfoliar pore network. For the static experiments, the relationships developed in the previous papers of this series regarding the dependence of the in-phase and quadrature conductivities on the water content and saturation remain valid. For the time-lapse experiments, we observed a decrease of the in-phase and quadrature conductivities over time. These trends can be fitted by a decaying exponential function. This behaviour is explained by the kinetics of the illitization process and its effect on the cation exchange capacity of the material. Induced polarization appears therefore as a promising technique to monitor the effect of hyperalkaline solutions associated with the leaching of concrete and permeating a bentonite seal in Deep Geologic Disposal facilities that could be potentially used for high-level and long-lived radioactive wastes.

Spectropolarimetric properties of vortex retarders

Vortex retarders are optical retarders with a uniform retardance, but with a fast axis that varies azimuthally over the area of the optic. This affects the radial and azimuthal polarization components of the incoming beam. The vortex retarders discussed here generate TEM10 and TEM20 Laguerre-Gaussian beams. While several varieties of these vortex retarders exist, designed to function at specific wavelengths, and a few studies have reported their use at those wavelengths, almost no data exists detailing their polarimetric properties outside those wavelengths. Using a Mueller matrix spectropolarimeter with dual-rotating retarders, the polarization properties of four zero-order half-wave vortex retarders have been measured across a broad wavelength range of 300–1100 nm. This data contributes to a more complete description of the spectral properties of these popular retarders.

A comparative study of radio signatures from winds and jets: modelling synchrotron emission and polarization

ABSTRACT Outflows driven by active galactic nuclei (AGNs) are seen in numerous compact sources; however, it has remained unclear how to distinguish between the driving mechanisms, such as winds and jets. Therefore, our study aims to offer observational insights from simulations to aid in this distinction. Specifically, in this paper, we investigate the evolution of wide-angled moderately relativistic magnetized winds and analyse their non-thermal radio emission and polarization properties. We find that the evolution of winds varies depending on factors such as power, density, and opening angle, which in turn influence their observable characteristics. Additionally, different viewing angles can lead to varying observations. Furthermore, we note distinctions in the evolution of winds compared to jets, resulting in disparities in their observable features. Jets typically exhibit a thin spine and hotspot(s). Winds manifest broader spines or an ‘hourglass-shaped’ bright emission in the cocoon, which are capped by bright arcs. Both display high polarization coinciding with the bright spine and hotspots/arcs, although these regions are relatively compact and localized in jets when compared to winds. We emphasize the importance of high resolution, as we demonstrate that emission features from both jets and winds can become indistinguishable at lower resolutions. The distribution of polarization is largely unaffected by resolution, though lower polarization becomes more noticeable when the resolution is decreased.

Long‐Infrared Broadband Polarization‐Sensitive Absorber with Metasurface Based on Ladder Network

AbstractPlasmonic resonant and metamaterial structures allow for manipulating the polarization properties of electromagnetic waves to achieve polarization beam splitting. Broadband polarization‐sensitive metamaterial absorbers based on surface plasmon polaritons have the advantages of high‐energy utilization and excellent stability, which may replace traditional polarizing devices. Here, an absorber based on a ladder network construction is designed theoretically and investigated experimentally. The absorber can possess almost 92% average absorptivity for TM polarization light in 8–12 µm range (experimental result: 83% from 7 to 11 µm). It is especially sensitive to the polarization angle of incident light, and with the increase of polarization angle, the broadband absorption response can present analogously monotonous reduction. The theoretical and experimental results for TE polarization light are 12% and 25%, respectively. The broadband absorption response performs angle insensitive property under oblique incidence. The proposed metamaterial absorber opens a path to realize broadband polarization‐sensitive absorption based on simple nanostructure. It will possess great potential applications in high‐performance polarimetric photodetectors and imaging fields.

The selenium substitution of solvent additive enables efficient polymer solar cells with efficiency of 19.4 %

Solvent additives, which are widely used as versatile tools for refining active layer morphology, have been considered as important role in enhancing the power conversion efficiency (PCE) of polymer solar cells (PSCs). Herein, innovative solvent additive 2,5-dibromoselenophene (BrS), is devised and synthesized by substituting the sulfur atom in 2,5-dibromothiophene (BrT) with selenium atom. The facile polarization properties of selenium atoms enable selenophene to participate in intermolecular interactions with oxygen or sulfur atoms. Therefore, incorporating BrS into the blend solution leads to refined intermolecular interactions and molecular packing, and crystallinity, resulting in a refined bulk heterojunction (BHJ) morphology compared to using the solvent additives 1-chloronaphthalene (CN) and BrT. Consequently, the BrS outperform their BrT and CN in improving photon absorption, exciton dissociation, and charge collection properties of PSCs, yielding an enhanced PCE of 18.0 % in PM6:Y6 BHJ devices. Moreover, the BrS solvent additive exhibit general applicability in both non-fullerene small molecules PSCs and all-polymer PSCs. High efficiency of 18.8 %, 19.4 % and 18.1 % are obtained in PM6:L8-BO, D18:L8-BO, and PM6:PY-IT BHJ solar cells, respectively, which is rankable among the paramount performance reported to date. Our results highlight the potential of selenophene-based solvent additives as an observable pathway for nanomorphology of active layer and effective enhancement of PCE in PSCs.

Multi-Axial Self-Driven X-Ray Detection by a Two-Dimensional Biaxial Hybrid Organic-Inorganic Perovskite Ferroelectric.

Metal halide perovskite ferroelectrics combining spontaneous polarization and excellent semiconducting properties is an ideal platform for enabling self-driven X-ray detection. However, achievements to date have been only based on uniaxiality, which increases the complexity of device fabrication. Multi-axial ferroelectric materials have multiple equivalent polarization directions, making them potentially amenable to multi-axial self-driven X-ray detection, but the report on these types of materials is still a huge blank. Herein, a high-quality (BA)2(EA)2Pb3I10 (1) biaxial ferroelectric single crystal was successfully grown, which exhibited significant spontaneous polarization along the c-axis and b-axis. Under X-ray irradiation, bulk photovoltaic effect (BPVE) was exhibited along both the c-axis and b-axis, with open circuit voltages (Voc) of 0.23 V and 0.22 V, respectively. Then, the BPVE revealed along the inversion of polarized direction with the polarized electric fields. Intriguingly, due to the BPVE of 1, 1 achieved multi-axial self-driven X-ray detection for the first time (c-axis and b-axis) with relatively high sensitivities and ultralow detection limits (17.2 nGyair s-1 and 19.4 nGyair s-1, respectively). This work provides a reference for the subsequent use of multi-axial ferroelectricity for multi-axial self-driven optoelectronic detection.

Effect of modulating monovalent ion doped on A-site high-entropy perovskites

High-entropy materials constitute solid solutions composed of five or more elements. This complex and diverse composition endows the materials with unique physical and chemical properties, presenting immeasurable value in material design. Despite such potential applications, the composition design still has deficiencies, and the influence mechanism of elements remains a research gap. In this work, a series of new high-entropy perovskites (La0.5X0.5)0.2(Ce0.5X0.5)0.2Ba0.2Sr0.2Ca0.2TiO3 (where X = Li, Na, K) were designed and synthesized. We systematically studied their phase structures, microscopic morphologies, as well as dielectric and ferroelectric properties. Notably, novel findings are reported. Specifically, (La0.5Li0.5)0.2(Ce0.5Li0.5)0.2Ba0.2Sr0.2Ca0.2TiO3 ceramics exhibit excellent breakdown field strength (Eb = 135 kV cm−1) and minimal leakage currents in 10−7–10−6 A cm−2. Moreover, the designed ceramics display exceptional dielectric constant (εr = 5 × 104) and saturation polarization (Ps = 2.8 μC cm−2) properties. These findings introduce novel insights into designing high-entropy ceramic components, enabling the customization of new dielectric and ferroelectric properties by manipulating doped monovalent ions.

Heat and mass transport micropolar Maxwell and Williamson nanofluids flow past a perpendicular cylinder using combined convective flow

The current study aims to investigate the heat and mass transport characteristics of micropolar Maxwell and Williamson nanofluids flowing past a perpendicular cylinder under the influence of combined convective flow using the Buongiorno nanofluid model. The objective is to analyze the axisymmetric flow of these nanofluids around an orthogonal cylinder, highlighting the effects of various physical parameters on temperature profiles and velocity distributions. Maple 23 software was employed to solve the coupled nonlinear differential equations derived from appropriate similarity transformations. The numerical results are presented in tabular and graphical form to show the impacts of key parameters on the selected micropolar nanofluids. The significant outcomes show that the skin friction coefficient, as well as the Nusselt and Sherwood numbers, increase along the axial direction, indicating enhanced heat and mass transfer capabilities. Additionally, the study emphasizes the roles of micro polarity, relaxation time, and viscoelastic properties in modulating these transfer processes. These findings have significant implications for applications in biomechanics, polymer manufacturing, aerosol deposition, and thermal treatment processes, offering valuable insights for future research and industrial practices.

Investigating the Impact of γ-Ray Radiation on the Aggregate Structure and Interfacial Polarization Properties of XLPE

Investigating the Impact of γ-Ray Radiation on the Aggregate Structure and Interfacial Polarization Properties of XLPE

Diffusosphere engineering in BNT-based multilayer heterogeneous film capacitors for high performance

Combining layers with high breakdown resistance and high polarization is a promising approach for designing dielectric capacitors with high energy density and efficiency. However, such combinations often accompany strong interfacial polarization, magnification of local electric fields, leading to premature breakdown. This work addresses this issue via controlled formation of diffusospheres. We constructed multilayer heterogeneous films using two Bi0.5Na0.5TiO3 (BNT)-based substances with high breakdown resistance and high polarization properties. Experimental results and finite element simulations demonstrate that the energy storage capacity of these films effectively harnesses the advantages of both phases. Notably, the interface polarization is minimal. Instead, a solid solution-like diffusosphere, formed by the mutual diffusion of ions between the two phases, plays a crucial role. The diffusosphere acts as a transition zone, mitigating charge aggregation at the interfaces and optimizing the relaxor and breakdown characteristics of the capacitor. With six diffusospheres, the multilayer heterogeneous capacitor achieves a recoverable energy storage density of 94 J/cm3, a significant advancement in BNT-based energy storage films. This work proposes and validates the concept of diffusospheres and their role in reducing interfacial polarization in multilayer heterogeneous films, enhancing the understanding of heterogeneous composite structures and advancing the field of dielectric energy storage.

Multidimensional Engineering Induced Interfacial Polarization by in-Situ Confined Growth of MoS2 Nanosheets for Enhanced Microwave Absorption.

Interface design has enormous potential for the enhancement of interfacial polarization and microwave absorption properties. However, the construction of interfaces is always limited in components of a single dimension. Developing systematic strategies to customize multidimensional interfaces and fully utilize advantages of low-dimensional materials remains challenging. Two-dimensional transition metal dichalcogenides (TMDCs) have garnered significant attention owing to their distinctive electrical conductivity and exceptional interfacial effects. In this study, a series of hollow TMDCs@C fibers are synthesized via sacrificial template of CdS and confined growth of TMDCs embedded in the fibers. The complex permittivity of the hollow TMDCs@C fibers can be adjusted by tuning the content of CdS templates. Importantly, the multidimensional interfaces of the fibers contribute to elevating the microwave absorption performance. Among the hollow TMDCs@C fibers, the minimum reflection loss (RLmin) of the hollow MoS2@C fibers can reach -52.0dB at the thickness of 2.5mm, with a broad effective absorption bandwidth of 4.56GHz at 2.0mm. This work establishes an alternative approach for constructing multidimensional coupling interfaces and optimizing TMDCs as microwave absorption materials.

INTEGRAL/IBIS polarization detection in the hard and soft intermediate states of Swift J1727.8−1613

Aims. Soft γ-ray emission (100 keV–10 MeV) has previously been detected in the hard state of several microquasars. In some sources, this emission was found to be highly polarized and was suggested to be emitted at the base of the jet. Until now, no γ-ray polarization had been found in any other state. Methods. Using INTEGRAL/IBIS, we studied the soft γ-ray spectral and polarization properties of Swift J1727.8−1613 throughout its outburst. Results. We detect a highly polarized spectral component in both the hard intermediate state and the early stages of the soft intermediate state above 210 keV. In the hard intermediate state, the polarization angle significantly deviates from the compact jet angle projected onto the sky, whereas in the soft intermediate they are closely aligned. This constitutes the first detection of jet-aligned polarization in the soft γ-ray for a microquasar. We attribute this polarized spectral component to synchrotron emission from the jet, which indicates that some of the jet might persist into the softer states.

Polarization analysis and filtering of undersampled 3C seismic data in the frequency-slowness domain

Polarization filters have emerged as a useful tool for coherent noise denoising in multicomponent seismic data. By exploiting the polarization properties of seismic waves, these filters can significantly improve wave-type separation, which is a crucial step in seismic data processing. However, their effectiveness in land seismic data in complex areas can be impacted by the presence of scattering noise, and their applicability is limited by irregular spatial sampling, which hinders velocity information for wave-type discrimination. To address these limitations, we introduce a novel two-step method for distinguishing and separating polarized wave types in shot gathers captured from a spatially undersampled linear array of 3C vector sensors. The first step involves conducting a polarization analysis in the frequency-slowness domain using elliptical elements derived from the linear Radon transform of the seismic data. The second step isolates specific polarized waves using the 3C frequency-slowness polarization filter (3C-FSPF), a technique that uses tailored taper functions based on polarization analysis. Our method stands out from single-station filters that cannot use velocity information for wave-type discrimination and existing multistation filters that require regularly sampled data. To evaluate our method, comprehensive tests are conducted on synthetic and real data. The results consistently demonstrate the effectiveness of 3C-FSPF in separating diverse polarized wave types under conditions of irregular and sparse spatial sampling and noise. Our findings underscore the potential of this method for advancing exploration geophysics by enhancing the quality of seismic data, particularly in land regions with complex near-surface structures.

Polarization characterization of a nonspherical sea salt aerosol model

The T-matrix method was utilized to study the polarization characteristics of nonspherical sea salt aerosol models within the wavelength range of 0.48–2.5 µm. Analysis was conducted on the polarization characteristics of nonspherical sea salt aerosols across different wavelengths as a function of scattering angle. This included scrutinizing linear depolarization ratios under typical visible and near-infrared wavelengths for various aspect ratios. The impact of particle nonsphericity on the linear depolarization ratios of monodisperse and polydisperse sea salt aerosol particles was examined. The results indicate: (1) In the analysis of the polarization characteristics of sea salt aerosols, the trends of polarization properties are similar between monodisperse and polydisperse systems. The scattering phase function P11(θ) is predominantly more significant in the forward-scattering direction. P11(θ) is insensitive to wavelength changes in the backward-scattering direction. P33(θ)/P11(θ) varies across different bands; in the visible light spectrum, there are significant fluctuating changes, while in the infrared spectrum, it trends towards nearly linear changes. The variation trends of −P12(θ)/P11(θ) and P34(θ)/P11(θ) with scattering angle are similar, and both are significantly affected by changes in wavelength. (2) Regarding the depolarization ratio of sea salt aerosols, the value for polydisperse systems is more than twice that of monodisperse systems, and the greater the nonsphericity, the higher the linear depolarization ratio. In monodisperse systems, at a wavelength of 0.633 µm for visible light and an aspect ratio of 0.4, the maximum depolarization ratio is around 118.82, while at 1.65 µm in the near-infrared, with an aspect ratio of 0.2, the maximum depolarization ratio is near 97.52; under polydisperse conditions, at 0.633 µm for visible light and an aspect ratio of 0.4, the maximum depolarization ratio is around 117.18, while at 1.65 µm in the near-infrared, with an aspect ratio of 0.2, the maximum linear depolarization ratio is near 215.66. Investigating the polarization characteristics and linear depolarization ratios of nonspherical spheroid sea salt aerosol particle models at all scattering angles is important for remote-sensing detection, high-precision calibration, and other optoelectronic applications.

Molecular Orientation-Dependent Photonic Polarization Engineering in Organic Single-Crystal-Filled Microcavities.

Designing the polarization degree of freedom of light is crucial in many fields and has widespread application in, for example, all-optical circuits. In this work, we find that in an organic microcavity filled with anisotropic single crystals the cavity modes can be modulated to be elliptically polarized, i.e., partially circularly polarized and partially linearly polarized. The circular polarization component originates from the Rashba-Dresselhaus spin splitting, while the linear polarization component is due to the dislocation of linearly polarized modes. The dislocation of the linear polarizations is ascribed to the orientation of individual molecules and the molecular packing arrangement; hence, the linear polarizations can be controlled by properly structuring the molecular distributions. Our results pave the way for enriching and engineering the polarization properties of individual optical cavity modes in organic microstructures, which may favor the development of polarized lasers with various polarizations.

Testing particle acceleration in blazar jets with continuous high-cadence optical polarization observations

Variability can be the pathway to understanding the physical processes in astrophysical jets. However, the high-cadence observations required to test particle acceleration models are still missing. Here we report on the first attempt to produce continuous, $>24$ hour polarization light curves of blazars using telescopes distributed across the globe, following the rotation of the Earth, to avoid the rising Sun. Our campaign involved 16 telescopes in Asia, Europe, and North America. We observed BL Lacertae and CGRaBS J0211+1051 for a combined 685 telescope hours. We find large variations in the polarization degree and angle for both sources on sub-hour timescales as well as a $ rotation of the polarization angle in CGRaBS J0211+1051 in less than two days. We compared our high-cadence observations to particle-in-cell magnetic reconnection and turbulent plasma simulations. We find that although the state-of-the-art simulation frameworks can produce a large fraction of the polarization properties, they do not account for the entirety of the observed polarization behavior in blazar jets.

Molecular self-assembled helix peptide nanotubes based on some amino acid molecules and their dipeptides: molecular modeling studies.

The paper considers the features of the structure and dipole moments of several amino acids and their dipeptides which play an important role in the formation of the peptide nanotubes based on them. The influence of the features of their chirality (left L and right D) and the alpha-helix conformations of amino acids are taken into account. In particular, amino acids with aromatic rings, such as phenylalanine (Phe/F), and branched-chain amino acids (BCAAs)-leucine (Leu/L) and isoleucine (Ile/I)-as well as corresponding dipeptides (diphenylalanine (FF), dileucine (LL), and diisoleucine (II)) are considered. The main features and properties of these dipeptide structures and peptide nanotubes (PNTs), based on them, are investigated using computational molecular modeling and quantum-chemical semi-empirical calculations. Their polar, piezoelectric, and photoelectronic properties and features are studied in detail. The results of calculations of dipole moments and polarization, as well as piezoelectric coefficients and band gap width, for different types of helical peptide nanotubes are presented. The calculated values of the chirality indices of various nanotubes are given, depending on the chirality of the initial dipeptides-the results obtained are consistent with the law of changes in the type of chirality as the hierarchy of molecular structures becomes more complex. The influence of water molecules in the internal cavity of nanotubes on their physical properties is estimated. A comparison of the results of these calculations by various computational methods with the available experimental data is presented and discussed. The main tool for molecular modeling of all studied nanostructures in this work was the HyperChem 8.01 software package. The main approach used here is the Hartree-Fock (HF) self-consistent field (SCF) with various quantum-chemical semi-empirical methods (AM1, PM3, RM1) in the restricted Hartree-Fock (RHF) and in the unrestricted Hartree-Fock (UHF) approximations. Optimization of molecular systems and the search for their optimal geometry is carried out in this work using the Polak-Ribeire algorithm (conjugate gradient method), which determines the optimized geometry at the point of their minimum total energy. For such optimized structures, dipole moments D and electronic energy levels (such as EHOMO and ELUMO), as well as the band gap Eg = ELUMO - EHOMO, were then calculated. For each optimized molecular structure, the volume was calculated using the QSAR program implemented also in the HyperChem software package.

New Fe3O4-Based Coatings with Enhanced Anti-Biofilm Activity for Medical Devices.

With the increasing use of invasive, interventional, indwelling, and implanted medical devices, healthcare-associated infections caused by pathogenic biofilms have become a major cause of morbidity and mortality. Herein, we present the fabrication, characterization, and in vitro evaluation of biocompatibility and anti-biofilm properties of new coatings based on Fe3O4 nanoparticles (NPs) loaded with usnic acid (UA) and ceftriaxone (CEF). Sodium lauryl sulfate (SLS) was employed as a stabilizer and modulator of the polarity, dispersibility, shape, and anti-biofilm properties of the magnetite nanoparticles. The resulting Fe3O4 functionalized NPs, namely Fe3O4@SLS, Fe3O4@SLS/UA, and Fe3O4@SLS/CEF, respectively, were prepared by co-precipitation method and fully characterized by XRD, TEM, SAED, SEM, FTIR, and TGA. They were further used to produce nanostructured coatings by matrix-assisted pulsed laser evaporation (MAPLE) technique. The biocompatibility of the coatings was assessed by measuring the cell viability, lactate dehydrogenase release, and nitric oxide level in the culture medium and by evaluating the actin cytoskeleton morphology of murine pre-osteoblasts. All prepared nanostructured coatings exhibited good biocompatibility. Biofilm growth inhibition ability was tested at 24 h and 48 h against Staphylococcus aureus and Pseudomonas aeruginosa as representative models for Gram-positive and Gram-negative bacteria. The coatings demonstrated good biocompatibility, promoting osteoblast adhesion, migration, and growth without significant impact on cell viability or morphology, highlighting their potential for developing safe and effective antibacterial surfaces.

Modulation of pseudo-brewster angle in a phase change material

The paper studies the angle of incidence required to achieve minimal reflectance for p-polarization, referred to as the pseudo-Brewster angle, within the context of a phase change material. By using a thin-film material such as vanadium dioxide (VO2), known for its phase transition from insulator to metal at 68 °C, which significantly alters the material's refractive indices, alongside an absorbing substrate like gold, we demonstrate the attainability of a pseudo-Brewster angle of zero. Moreover, this angle may be modulated by a wide margin during the phase transition. These findings are potentially interesting for balancing s- and p-polarizations and facilitating efficient control over light polarization properties.

Volatile memory characteristics of CMOS-compatible HZO ferroelectric layer for reservoir computing

Recently, ferroelectric memory utilizing hafnium oxide has emerged as an attractive option compared to existing memory technologies, primarily due to its scalability and energy-efficient advantages. Among them, hafnium zirconium oxide (HZO) is examined for its short-term memory characteristics to achieve a reservoir computing system known to exhibit remarkable polarization properties, being able to switch between distinct polarization states under the influence of an electric field. These unique properties are of utmost importance in ferroelectric memory applications, where they play a pivotal role in the storage and retrieval of binary data. In this study, we identify and experiment with the electrical characteristics of a ferroelectric tunnel junction (FTJ) device with a metal-ferroelectric-semiconductor (MFS) structure using TiN as the top electrode and HZO as the ferroelectric layer. Moreover, we assess the performance of the device by evaluating its maximum 2Pr (remnant polarization) and tunneling electro resistance (TER) values in different conditions of cell area. Furthermore, we analyze and show short-term memory (STM) characteristics and synaptic properties with 5 cycles of potentiation and depression under conditions of stable dynamic range by coordinating identical and incremental pulses. In the case of incremental pulses (>95 %), the MNIST pattern recognition accuracy is higher than in the case of identical pulses (>94 %). Through a sequence of procedures, the synaptic characteristics of FTJs are confirmed to assess their suitability for use as an artificial synaptic device.