Dielectric Parameters Research Articles

The impact of Bi3+ ions on magnetization, dielectric parameters, and conductivity of soft Mg-Cu ferrite nanoparticles

This paper investigates the bismuth ions leverage on magnetic and dielectric features of magnesium–copper nanoferrites Mg0.5Cu0.5BixFe2-xO4 (MCBF). The Mg0.5Cu0.5Bi0.1Fe1.9O4 nanoferrite exhibits superior magnetic properties compared to the pure Mg-Cu sample. These properties include a higher magnetization of 31.31 emu/g, with an enhancing ratio of 1.50 %. Additionally, it demonstrates a higher initial permeability of 17.84, with an enhancing ratio of 55.12 %. Furthermore, their coercivity is lower at 59.90 Oe, with an enhancing ratio of 50 %. All MCBF nanoferrites exhibit a high-frequency response between 6.106 and 6.926 GHz, making them suitable for microwave technology. The dielectric parameters dispersion shows normal behavior at different frequencies and temperatures. As for dielectric parameters dependence on Bi content, it exhibited a peculiar manner. At a temperature of 297 K and a frequency of 50 Hz, the nanoferrite Mg0.5Cu0.5Bi0.1Fe1.9O4 exhibits superior dielectric properties compared to the pure Mg-Cu sample. Specifically, it demonstrates the highest dielectric constant of 360.68, with an enhancing ratio of 125.97 %. Additionally, it displays the highest conductivity of 691.4 µ(Ω.m)-1, with an enhancing ratio of 1543.23 %. Furthermore, the nanoferrite exhibits a lower dielectric loss of 6.49, with an enhancing ratio of 80.22 % compared to the pure Mg-Cu sample. The conduction mechanism of the Mg0.5Cu0.5BixFe2-xO4 nanoferrites was determined by fitting the σac results via the Jonscher power law. This conduction mechanism is attributed to correlated barrier hopping (CBH) model up to 473 K, followed by small polaron tunneling (SPT), which reaches higher temperatures. Hence, the Mg0.5Cu0.5Bi0.1Fe1.9O4 nanoferrite has a remarkable magnetic and dielectric nature, which can be used as functional soft ferrite material in transformers and high-frequency electronic devices.

An EXPERIMENTAL STUDY ON DIELECTRIC PARAMETERS OF XLPE INSULATED HIGH VOLTAGE CABLES UNDER DIFFERENT OPERATING CONDITIONS

High voltage underground cables used in distribution systems provide benefits including aesthetics, reliability, low maintenance costs, and resistance to environmental factors. However, their initial installation expenses are considerably higher than overhead lines, and fault detection is quite challenging. Thus, a deep analysis of dielectric parameters is crucial. Typically, electrical specifications of high voltage underground cables provided by the manufacturer are used for nominal operating conditions. However, it is essential to acknowledge that variations in operational conditions have a discernible impact on the dielectric characteristics of cable insulation. This phenomenon results in an accelerated aging process of the insulation material and contributes to unexpected failures. Hence, it is imperative to determine dielectric parameters of cable insulation under varying operational conditions and elucidate the impact of these operational states on insulation properties. This study involved experimental determination of the dielectric parameters, including capacitance, relative dielectric constant, dielectric loss, and tanδ, for a XLPE insulated high voltage underground cable, designed for a nominal voltage of 12/20 kV. These assessments were performed under varying operating conditions, specifically for distinct voltage, temperature, and frequency. Based on the acquired findings, it is evident that the dielectric characteristics of the cable insulation exhibit substantial variations in response to alterations in voltage, temperature, and frequency, even when operating within the defined nominal limits.

The Origin of Collective Dielectric Relaxation Process in Ferroelectric and Antiferroelectric Phases of Liquid Crystals

Dielectric spectroscopy has proven as an important tool for the characterization of ferroelectric and antiferroelectric phases observed in the thermotropic chiral liquid crystals compounds. These compounds generally have paraelectric smectic A (SmA*) phase, ferroelectric smectic C (SmC*) phase and antiferroelectric smectic C (SmCA*) phase. In some compounds, ferroelectric (SmCg*) phase is also found. Dielectric spectra of these phases under planar alignment of the molecules are sometimes complex but rich in information and are very helpful in the determination of the structure of these phases. In the SmA* phase, a mode in high kHz region is observed. In the SmC* phase, a relaxation mode observed in low kHz region having high dielectric strength. However, in the SmCg* phase observed mode relaxation frequencies lies in same frequency window as SmC* phase but their dielectric strength was less than at least one order magnitude in comparison to observed mode of SmC* phase. In the SmCA* phase, dielectric spectrum contains two relaxation modes observed in kHz and MHz regions respectively. The dielectric strengths of these two modes are very small and less than at least one/two order magnitude in comparison to observed mode of SmA*/ SmC* phases. These observed relaxation processes are discussed as a function of temperature and bias electric field and their origin is also examined in the light of the experimental work. Dielectric parameters of the above phases observed in such material are discussed with regards to their structure property relationship.

Aggregation Behavior of Ethoxylated Phytosterol Surfactants in Different Protic Solvents: An Insight from Dielectric Relaxation Studies.

The micellar aggregation behavior of biocompatible surfactants, phytosterol ethoxylates (BPS-n, n is the oxyethylene (EO) chain length), containing polyoxyethylene chains in four organic solvents (glycerol (G), ethylene glycol (EG), formamide (FA), and N,N-dimethylformamide (DMF)) was studied by dielectric spectroscopy in the frequency range of 40 Hz to 110 MHz. Only the BPS-n/EG and BPS-n/G systems show distinct dielectric loss peaks near 104 Hz, indicating that BPS-n forms micellar aggregates in EG and G solvents, and the interfacial polarization (IP) between the aggregates and solvents leads to this relaxation. The dielectric spectra were analyzed based on the IP theory and a columnar dispersion model. The dielectric parameters of micelles, the permittivity and conductivity of micelles and solvents, and the volume fraction of the aggregates in solvents were calculated. On this basis, the binding numbers of each EO group on the hydrophobic chain to the solvent molecules EG and G were calculated to be 0.42 and 0.22, respectively. It was suggested that the aggregation appears to be related to the magnitude of the hydrogen bonding interactions. The lower number of EO group-binding solvents is because of the strong steric effect of alcohol solvents and the magnitude of the hydrogen bonding force.

Calculation and Measurement of Dielectric Parameters of Ceramic and Ferroelectric Materials in the Microwave Range

Introduction. Determination of the electrophysical parameters of linear and nonlinear dielectric materials for use in microwave technology represents an important direction. Linear dielectrics are used as a basis for the substrates of microwave circuits, as well as volumetric elements for the construction of frequency selective or resonant structures that operate across a wide temperature range. Therefore, the issue of stabilizing the electrical parameters of such structures from temperature influences appears relevant. A possible solution lies in the use of a multilayer combination of dielectrics, both with linear and nonlinear properties. Due to their nonlinear properties, ferroelectrics find application in functional units with an electrical rearrangement of frequency and phase characteristics. Therefore, it is important to determine not only the relative permittivity of the material, but also the control coefficient in the RF– microwave wavelength ranges.Aim. Construction of computational mathematical models for layered bulk and film structures to determine the relative permittivity of linear and nonlinear dielectrics in the ultrahigh frequency range.Materials and methods. The construction of computational mathematical models for the analysis of complex layered structures was carried out on the basis of Maxwell’s equations and the Galerkin method using boundary conditions for electromagnetic field components.Results. An electrodynamic analysis of a two-layer volumetric disk resonator was performed, and numerical results of calculating the resonant frequency were obtained. A numerical analysis of a multielectrode half-wave resonator with a ferroelectric film (FEF) was carried out.Conclusion. The mathematical models created and the experiment performed made it possible to numerically evaluate the properties of linear and nonlinear dielectric bulk and film materials in the microwave range.

Estimation of SAR Average in Rats during 5G NR Chronic Exposure

To study physiological reactions in the brain and skin of higher mammals exposed to chronic radiofrequency radiation, specific absorption ratio (SAR) determination is required and time-consuming numerical methods are used. The paper deals with the estimation of the whole-body specific absorption rate (SAR) in rats chronically exposed to external electromagnetic fields, as well as the development of a laboratory setup simulating the operation of a fifth-generation 5G New Radio base station (with a signal bandwidth of 15 MHz and a carrier frequency of 2.4 GHz). The paper presents a modified method for theoretical SAR estimation for one-sided irradiation and distributed absorption. Mean whole-body SAR values were estimated by the proposed method and numerically modeled with the CST Microwave Studio simulation software 2020package using primitive rat models. Dielectric parameters in the numerical simulation were used from the software library. The IEEE/IEC 62704-1 algorithm was used to investigate SAR in numerical simulations. The theoretical estimates and numerical simulations were compared for different SAR distributions and were found to be qualitatively comparable. The differences between approximate theoretical estimates and numerical simulations are 7% and 10% for distributed and non-distributed absorptions, respectively. The proposed method, which takes into account the decreasing power flux density, can be used to estimate the approximate whole-body SAR during chronic electromagnetic field exposure in rats.

Structural, thermal, optical, magnetic and electrical properties of Fe doped Ba0.77Ca0.23TiO3 perovskite

The most known ferroelectric ceramic material is Barium Titanate (BaTiO3), which is frequently used in actuators, capacitors, and memory devices. The ferroelectric properties of Barium Titanate were improved by doping a small amount of other dopants. Choosing a material with high ferroelectric, piezoelectric, dielectric, and magnetic constants, low dielectric loss, and high electrical resistivity is necessary. In order to achieve the purpose, the suggested sample is formed as Ba0.77Ca0.23Ti1-xFexO3, where x is equivalent to 0.0, 0.05, 0.15, and 0.20. We doped iron (Fe), replacing titanium, and the percentage of calcium was fixed. The composition was synthesized by the conventional solid-state reaction (SSR) method. Effects of ferrite contents (x) on the structural, thermal, optical, dielectric, magnetic, and electrical properties were thoroughly investigated. The structural properties and phase identification were studied by powder X-ray diffraction (XRD), confirming the formation of the cubic crystal structure of perovskite samples. While increasing Fe contents (x), the lattice parameter of the samples increases slightly but dramatically decreases for x = 0.20. Differential Scanning Calorimeter (DSC) results that the specific heat capacity is highest at 1100 °C. Fourier-transform infrared spectroscopy (FTIR) analyses confirmed the metal-oxygen corresponding bonds at 370 cm−1 and 530 cm−1 in the perovskite structure. The bandgap (Eg) values decrease from 2.46eV to 1.75eV with Fe added in the sample studied by exploiting ultraviolet–visible spectroscopy (UV–Vis). The magnetization increases with the addition of an applied magnetic field and Fe contents. The dielectric parameters, permeability, impedance, and AC resistivity have been extracted from the measurement of the Impedance Analyzer. As band gap energy decreases, the compositions can be good candidates for memory devices. Low magnetization can make these compositions a good choice for spintronics, memory devices, and catalysis.

Electrophysical Properties of the Three-Component Multiferroic Ceramic Composites.

Using the free (pressureless) sintering method, multiferroic ceramic composites based on two ferroelectric materials, i.e., BaTiO3 (B) and Pb0.94Sr0.06 (Zr0.46Ti0.54)0.99Cr0.01O3 (P), and magnetic material, i.e., zinc-nickel ferrite (F) were obtained. Three composite compositions (BP-F) were obtained with a constant 90/10 content (ferroelectric/magnetic) and a variable content of the ferroelectric component (B/P), i.e., 70/30, 50/50, and 30/70. Crystalline structure, microstructural, DC electrical conductivity, dielectric, and ferroelectric properties of multiferroic composites were investigated. The concept of a composite consisting of two ferroelectric components ensures the preservation of sufficiently high ferroelectric properties of multiferroic composites sintered by the free sintering method. Research has shown that the percentage of individual ferroelectric components in the composite significantly affects the functional properties and the entire set of physical parameters of the multiferroic BP-F composite. In the case of the dielectric parameters, the best results were obtained for the composition with a more significant amount of BaTiO3; i.e., permittivity is 1265, spontaneous polarization is 7.90 µC/cm2, and remnant polarization is 5.40 µC/cm2. However, the most advantageous set of performance parameters shows the composite composition of 50BP-F.

Effect of 105 MeV gold ion irradiation on dielectric properties of PVC/PVDF@BaZrO3 nanohybrid thin film

The PVC/PVDF@BaZrO3 nanohybrid thin films were prepared by solution grown method. The dielectric constant of the films was higher due to BaZrO3 incorporation in the PVC/PVDF matrix. The PVDF and PVC/PVDF nanohybrid films were irradiated with 105 MeV Au2+ ion beam under vacuum condition at room temperature with two ion fluence. The irradiated thin film of PVC/PVDF@BaZrO3 exhibits relatively low dielectric constant with low loss at different temperature because of thermodynamic stability of β-phase. However, almost complete amorphization was observed in BaZrO3 filler in PVC/PVDF@BaZrO3 nanohybrid samples. After being irradiated with a 105 MeV Au2+ ion beam, the (ϵ′) dielectric constant, FTIR and SEM parameters were used to evaluate changes in dielectric and structural properties for all the samples. In FTIR spectra, new peaks appeared at 1705 cm−1, disappeared or minutely shifted due to high energy of ion beam. It is interesting to note that BaZrO3 phase becomes amorphized through 105 MeV Au2+ ion irradiation that causes an increased dielectric constant along with cross-linking effect of nanohybrid films.

Intrinsically self-healing ethylene-anisylpropylene copolymer as a candidate material for innovative electrical insulation layers

A novel ethylene-anisylpropylene copolymer was tested as a candidate material for intrinsically self-healing electrical insulation layers. In addition to the thermal and mechanical properties, the dielectric properties were studied before and after induced mechanical and electrical damage to the specimens. The material was tested according to the standards for electrical insulating materials, which require a detailed characterization of the dielectric properties. Nonstandardized tests of self-healing were also included in the testing. The results revealed that the tested material exhibited excellent dielectric parameters and reasonable thermal and mechanical properties. The self-healing tests of the material revealed a 38 % efficiency for recovery of the mechanical properties after the first damage, and this remained almost unchanged after the second and third damage. The first initial results also indicated that the material recovered, to some extent, its electrical insulation properties even after electrical breakdown. By comparing the dielectric strength of the pristine and self-healed specimens, a promising self-healing efficiency of 63 % was determined.

Interfacial effect on the microwave absorption properties in Y3Fe5O12/Fe2O3

In this work, the interfacial effect on the electromagnetic wave (EMW) absorbing performance in Y3Fe5O12 and Fe2O3 material system synthesized by one-step sol–gel method followed by various sintering temperature was studied. The synthesized samples were first characterized by performing x-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) measurements. A linear dependence of the saturation magnetization with the YIG content in the samples was observed that the saturation magnetization increases from 4.18 to 20.2 emu/g when the YIG crystal content is increased from 43 % to 88 %. Then, the EMW absorbing performance were studied by measuring dielectric parameters of the samples in the X-band. The experimental results indicate that the higher sintering temperature reduce the intensity of Fe2O3 peaks and enhance the formation of YIG chemical structure. Due to the both Fe2O3 and YIG crystal phases, the Fe2O3/Y3Fe5O12 interface enhances the EMW polarization and thus EMW absorbing performance. The minimum reflection loss was determined as −15.4 dB at 9.5 GHz frequency in YF1000 sample. The experimental results demonstrate that the sintering temperature has the prominent effect on the structural, magnetic and EMW absorbing properties of YIG. The results would be useful for the YIG-based microwave device applications.

Study on the effect of positive nematic liquid crystalline physical parameters on EHD properties

ABSTRACT The paper investigated the effects of viscous, elastic and dielectric parameters on the EHD performance of a positive nematic liquid crystal 5CB using CFD (CFD stands for Computational Fluid Dynamics) method. The governing equations including the continuity, momentum and angular momentum equation are presented. The constitutive equations for viscoelastic deformation and shear stress were established based on the L-E and O-F theories. The variables of micro-flow velocity, 5CB molecular director angular velocity, etc were chosen as the EHD (EHD is the abbreviation for electrohydrodynamic dynamics) feature quantities. The application of a DC electric field can cause continuous stable micro-flow in LC cell. The magnitude and direction of micro-flow are coupled with the angular velocity of the 5CB directors and are also influenced by viscoelastic parameters. The relaxation time is inversely proportional to the electric field intensity and dielectric parameters, proportional to the viscous parameters, and independent of the elastic parameters. Using the micro-PIV experiments, the numerical simulation results were tested. A stable approximate antisymmetric ‘S’ type flow profile was obtained in the 5CB cell which is in good agreement with the simulation result. The conclusions can lay a theoretical foundation for further study and application of liquid crystalline microfluidic driving methods.

Dielectric and structural properties of double-sintered (Na1-xKx)NbO3, (0.460 ≤ x ≤ 0.485) ceramics

Ceramic samples of Na1-xKxNbO3, (0.460 ≤ x ≤ 0.485) were prepared by using the double sintering solid-state reaction method. The grain size and porosity were found to vary with composition. The dielectric constant of the material phase was obtained from the measured dielectric constant of the prepared ceramic pellets by applying porosity correction. Among the prepared compositions, the dielectric constant was observed to be minimum for x = 0.475. The temperature variation of the dielectric constant and lattice parameters was measured for the samples with x = 0.475, in the range from room temperature (RT) to 500 °C. Three distinct phase transitions, monoclinic to tetragonal, at about 205 °C; tetragonal to tetragonal, at about 410 °C; and tetragonal to cubic, at 460 °C, were observed from the dielectric constant and high-temperature X-ray diffraction (HT-XRD) measurements of the prepared compositions.

Frequency response of dielectric relaxation modes in a room temperature antiferroelectric phase liquid crystalline mixture

Thermodynamic, optical, and electrical characterization of a newly formulated mixture of chiral mesogenic molecules has been carried out. The material exhibits different mesophases like paraelectric smectic (SmA*), ferroelectric chiral smectic (SmC*) with synclinic structure, and wide temperature range antiferroelectric chiral smectic (SmCa*) with anticlinic structure. These studies show that at room temperature, the SmCa* phase is present in a wide temperature range of ∼128 °C (from −35.0 °C to 92.6 °C) followed by the SmC* phase (from 92.6 °C to 110.8 °C) as well as SmA* phase (from 110.8 °C to 113.9 °C). Besides the wide temperature range, the SmCa* phase has also been optimized for high helical pitch length, which is useful for helix unwound cells through surface stabilization for application. Frequency-dependent dielectric parameters have been determined for the material in the frequency range of 1 Hz to 40 MHz. The dielectric spectroscopy shows six different relaxation modes in various phases due to the collective and individual molecular behavior. The SmA* phase exhibits soft mode relaxation associated with variations in the amplitude of the tilt angle. The identified soft mode is significantly temperature-dependent. Using the Curie-Weiss law, the transition temperature for the paraelectric SmA* phase to the ferroelectric SmC* phase (Tc) is found to be 111.4 °C. Two relaxation modes in the SmC* phase have been identified Goldstone mode and a domain mode. These modes have extremely high dielectric strength resulting in high permittivity in comparison with other modes. Three modes of relaxation have been detected in the antiferroelectric SmCa* phase. Different characteristic parameters of these modes are strongly temperature-dependent. This study signifies that the present room-temperature antiferroelectric liquid crystals may be a potential candidate for display applications.

A brief review on optical properties of polymer Composites: Insights into Light-Matter interaction from classical to quantum transport point of view

In recent years, the optical capabilities of polymer composites have dominated the marketplace for applications in optoelectronic and energy devices. Supercapacitors, light-emitting displays, optical waveguide sensors, and organic photovoltaic cells are a few examples of the applications of the optical behavior of composites. Polymer composites are composed of nano/micro-sized inorganic particles (such as semiconductors, metal complexes, and synthetic nanoparticles) that are distributed within a polymer matrix. These materials have a significant role because they combine the optical properties of inorganic materials with the ease of processing of polymers, which utilizes the potential and performance of polymer-based optical systems.Optical features of polymer composites, such as indices of refraction, transparency, dispersion, and coefficients of absorption, influence their potential uses in optical systems and devices. The purpose of this research is to establish more insight into the optical characteristics of polymer composites and to understand the correlations between the structure and optoelectronic behavior of polymer composites. This review involves general concepts, scientific guidelines, and feasible mathematical sections. The unique optical characteristics of some common polymers (PEO, PMMA, PVA, and CS) and polymer composites are briefly reviewed. This review article establishes the fact that metal complexes are excellent over ceramic filler or nano-particles to improve optical absorption and decrease the optical band gap. An inspection of the fundamentals of light-matter interaction, ranging from classical (Drude-Lorentz model) to quantum methods for studying electron transition was exhibited. Furthermore, the applications of Tauc’s model and optical dielectric loss parameters to estimate the optical energy band gap of polymer composites are explained. Other fundamental optical parameters, such as absorption coefficient, optical dielectric constant, and refractive index are also explored. Finally, the Wemple-DiDomenico (WD) model is applied to investigate; the refractive index, optical dielectric constant, and optical spectra moments. The correlations between the optical dielectric function and several parameters such as ε∞, τ, N/m*, µopt, ρopt, ωp, and Eg are derived. Various models based on refractive index and absorption coefficient are discussed in detail to estimate crucial optical parameters.

Ionic doping engineered Ce2(Zr1−xBx)3(MoO4)9 (B[dbnd]Cd1/3Nb2/3, Cd1/3Ta2/3) ceramics: Structural, chemical bond, and microwave/terahertz dielectric performance

A series of Ce2(Zr1−xBx)3(MoO4)9 ceramics, where BCd1/3Nb2/3, Cd1/3Ta2/3 (abbreviated as CZ1−xNx, CZ1−xTx), were synthesized using the classical solid-state reaction method. This study focused on the intrinsic mechanisms affected by doping in terms of chemical bond parameters, polarizability, lattice parameters, and bond valence. X-ray diffraction (XRD) results showed that Cd/Nb and Cd/Ta were solidly dissolved into the matrix lattice, which crystallized in a pure trigonal structure (Space group of R-3c, No. 167). According to the Phillips-van Vechten-Levine (P–V-L) theory, the chemical bond features have been parameterized for exploring the relationships between crystal structure and property. Interestingly, the findings indicated that the dielectric parameters varied closely with the chemical bond features of Zr1–O4. Far-infrared reflectivity (FIR) spectrum and terahertz time-domain (THz-TD) were used to obtain information on lattice vibration. The results showed that the complex permittivity extrapolated from THz-TD was closer to the measured value (at microwave) than the former. The relaxation polarization mechanism may be a key intrinsic factor affecting dielectric loss. Additionally, the bond valence results showed a linear relationship between Zr1–O4 and τf. CZ1−xNx and CZ1−xTx exhibited Qf values that were 2.86 and 5.46 times greater than the matrix, respectively, with low permittivity (εr, roughly 10) suitable for high-frequency communication materials. Notably, CZ0.94T0.06 ceramic achieved excellent performance with Qf = 103,974 GHz, εr = 10.63, and τf = −17.68 ppm/°C at 725 °C.

Impact of (Sm, Sr) Co-Doping at Bi-Site on the Structural, Optical, Multiferroic and Dielectric Properties of Bismuth Ferrite Nanocomposites

A series of samarium (Sm) and strontium (Sr) co-doped BiFeO3 (BFO) and pure BiFeO3 (BFO) nanocomposites were synthesized by thesol-gel auto-combustion method. The X-ray diffraction pattern of the synthesized Sr:Sm BFO nanocomposites shows a rhombohedralperovskite structure. The morphological studies revealed that synthesized Sr:Sm BFO and pure BFO exhibit a regular arrangement ofgrains. The diffuse reflectance spectra (DRS) exhibit the doping of Sr:Sm BFO reduces the optical band gap values of BFO from 2.02 eVto 1.69 eV. It was observed that the prepared Sr:Sm BFO and undoped BFO samples show G-type antiferromagnetic behaviour and thevalues of saturation magnetization (Ms) increased by increasing the Sr:Sm BFO doping concentrations at the A site of BFO lattice. Themagnitude of the dielectric constant (εr) and dielectric loss (tan δ) were increased gradually with applied frequency and by increasingdoping concentration in the BFO matrix. The significant enhancement in the dielectric parameters with increasing Sm and Sr concentrations in BFO results in improved ferromagnetic properties that could be considered a promising candidate for some advanced device applications.

A Study on Heat and Flow of Viscoelastic Dielectric Liquid Over an Inclined Stretching Sheet

Exploring the behavior of viscoelastic dielectric liquids on an inclined stretching sheet involves a comprehensive mathematical analysis. Employing a Runge-Kutta-based shooting strategy, this study delves into the system's non-linear Ordinary Differential Equations (ODEs). The research investigates how physical parameters like the Prandtl number, dielectric interaction parameter, viscoelastic parameter, Grashof number, and angle of inclination influence both velocity and temperature. Through graphical representations, the study sheds light on the impact of these factors and compares its findings with existing data. This intriguing combination of dielectric liquid behaviour under varying inclinations holds significant potential applications in Mines, Materials, and Fuels.

Ab initio studies of newly proposed zirconium based novel combinations of hydride perovskites ZrXH3 (X = Zn, Cd) as hydrogen storage applications

Using the WIEN2k code, first-principles simulations of ZrXH3 (X = Zn, Cd) hydride perovskites are performed to determine their hydrogen storage properties. The purpose of this study is to investigate their structural, optoelectronic, hydrogen storage, mechanical and thermoelectric properties. The structural analysis demonstrates their stability through the heat of formation along with desorption temperature and shows that these compositions belong to the orthorhombic space group Cmcm (no.63). The band structure and density of states are estimated for electronic characteristics, indicating the metallic nature of both compositions. Analysis of elastic properties such as elastic constants, Pugh’s ratio, bulk modulus, Poisson’s ratio, and anisotropy factor are explored to determine the mechanical stability of these compositions and demonstrate their suitability as a transport medium in hydrogen storage systems even at higher pressure. To study the optical behavior of the perovskites under consideration for hydrogen storage applications, the dielectric parameters, dielectric constants, refractive index, optical conductivity, absorptivity, and energy loss function are studied. The present paper represents the initial theoretical effort toward future exploration of these materials for hydrogen storage applications.

Effect of replacing B2O3 with Dy2O3 on the structural, physical, and radiation shielding properties of sodium boroaluminate glass

AbstractIn this work, some transparent aluminum sodium borate-based glasses containing Dy2O3 have been prepared using the melt quenching method. The incorporation of Dy3+ ions in the glass network leads to increase and decrease the density and molar volume, respectively. The structural properties are investigated by XRD and FTIR spectroscopy. It is revealed that addition of Dy2O3 causes a conversion of boron coordination from BO4 to BO3, which indicates the increase in the number of non-bridging oxygen. Therefore, the optical band gap is found to decrease as the Dy3+ ions content increases. The temperature dependences of dielectric constant and AC conductivity are studied at different frequencies. The electric conductivity and dielectric parameters decrease with increasing Dy3+ content due to the decrease in Na+ ions mobility due to the blocking effect of Dy3+ cations in the glass network. The shielding factors have been evaluated for the prepared glasses with the help of Phy-X program. The maximum linear attenuation coefficient (LAC) is found at 0.284 MeV and varied between 0.125 and 0.140 cm−1. The results revealed that the incorporation of Dy2O3 into the glasses has a substantial effect on the Zeff.. The value of the Zeff for the D1 sample, which does not include any Dy2O3, stays relatively the same, ranging around 7.51. We found that the rate of reduction in Zeff was significantly high when the energy of the photons is smaller than 0.826 MeV. From the Zeff data, we found that the addition of Dy2O3 to the glasses improves both their capacity to absorb and their capability to scatter ionizing radiation.