In this paper, a series of Sr0.96Al2Si2O8 phosphors doped with 0.02Eu2+ and 0.02Re3+ (where Re = Tm, Dy, Er, Nd, Sm, La, Ho) were synthesized using the high-temperature solid-phase method at 1350 °C for 4 hours. The samples underwent characterization for structural and phase analysis using XRD-6000. Fluorescence and photostimulated properties were evaluated with F-4600. The pyroluminescence curve indicates a trap depth of 0.6-0.8 eV for Sr0.96Al2Si2O8: 0.02Eu2+, 0.02Re3+ (where Re = Dy, Er, Sm, La, Ho), making it suitable for prolonged afterglow luminescence. In comparison with deep trap material Sr0.96Al2Si2O8: 0.02Eu2+, 0.02Nd3+, the generated traps approach or exceed 1 eV, suggesting its potential for use as a light excitation and optical storage material. Additionally, the correlation between sample TL and PSL was examined, confirming that the augmentation of initial photostimulated luminescence intensity is closely associated with the generation of new traps. Furthermore, considering the effect of different trivalent lanthanide rare earth ion doping on trap depth from a trap regulation perspective offers a potential avenue for elucidating the nuanced processes underlying photostimulated luminescence.
In this work, we have prepared the RE3+ (re = Sm, Dy): MgLa2V2O9 phosphors of different mol% by solid-state reaction approach. The obtained powder phosphors of RE3+ (re = Sm, Dy): MgLa2V2O9 were analyzed by SEM, XRD, FTIR, EDAX, PL spectroscopy, and CIE chromaticity diagram of the color of different mol%. The XRD pattern of the powder phosphors exhibits the phosphor's crystalline nature. The obtained size of prepared phosphors is around the size of 500 nm was observed by analysis of SEM. The element's existence in the phosphors was obtained by analysis of EDAX. Functional groups were identified by FTIR analysis. From the PL analysis SE3+ (re = Sm, Dy): MgLa2V2O9 phosphors show intense orange-red emission at 599 nm, that is attributed to the (4)G(5/2 )-> H-6(7/2) transition having an excitation lambda(exci)=404nm (6H(5/2 )-> F-4(7/2)). It exhibits yellow emission for Dy3+ (re = Sm, Dy): MgLa2V2O9 at 574 nm having a transition of F-4(9/2 )-> (6)H(13/2 )having an excitation wavelength lambda exci.= (H-6(15/2)-> I-4(15/2)). The CIE diagram shows the orange and yellow emission for Sm3+: MgLa(2)V(2)O(9 )and Dy3+:MgLa2V2O9 correspondingly. The CIE coordinates shows that the great purity of color of the phosphors powder.
Motivated by the recently discovered superconductivity in Sr-doped nickelate oxides NdNiO2, we predict a material BiNiO2 that provides an opportunity to study the intertwined ferroelectricity, metallicity, and magnetism in a crystal with very simple atomic structures.There is a ferroelectric structural transition from the nonpolar phase with the P4/mmm space group to the polar phase with the P4mm space group, which is driven by the lone pair on Bi.Calculations based on the Heyd-Scuseria-Ernzerhof hybrid density functional reveal that both the nonmagnetic and ferromagnetic states are metallic for nonpolar and polar phases, while the lowest energy ground-state for polar BiNiO2 is a Hubbard Mott insulator with the G-type antiferromagnetic spin configurations.As a ferroelectric material with an electric polarization of 0.49 C/m 2 , it may be possible to control the magnetic order in BiNiO2 by an applied electric field.The replacement of Nd by Bi serves as a connecting link between a high-temperature superconductor and a Mott multiferroic.Our work supports a route towards strongly correlated ferroelectrics.
In this work, we have prepared the RE3+(Sm, Dy): MgLa2V2O9 phosphors of different mol% by solid-state reaction approach. The obtained powder phosphors of RE3+(Sm, Dy): MgLa2V2O9 were analyzed by SEM, XRD, FTIR, EDAX, PL spectroscopy, and CIE chromaticity diagram of the color of different mol%. The XRD pattern of the powder phosphors exhibits the phosphor's crystalline nature. The obtained size of prepared phosphors is around the size of 500 nm was observed by analysis of SEM. The element's existence in the phosphors was obtained by analysis of EDAX. Functional groups were identified by FTIR analysis. From the PL analysis Sm3+: MgLa2V2O9 phosphors show intense orange-red emission at 599 nm, that is attributed to the 4G5/2→6H7/2 transition having an excitation λexci=404nm (6H5/2→4F7/2). It exhibits yellow emission for Dy3+: MgLa2V2O9at 574 nm having a transition of 4F9/2→6H13/2having an excitation wavelength λexci.= (6H15/2→4I15/2). The CIE diagram shows the orange and yellow emission for Sm3+: MgLa2V2O9 and Dy3+:MgLa2V2O9correspondingly. The CIE coordinates shows that the great purity of color of the phosphors powder.
In the framework of the density functional theory electronic band structure and density of states of LaxBa1-xMnO3 solid solutions containing different concentrations of La and Ba atoms, were studied using different exchange correlation functionals. Our calculation show that the band gap, which characterizes the properties of semiconductors, varies depending on the concentration of La and Ba atoms in the compounds. Using such a dependence, it is possible to make changes in physical properties depending on the concentration of cations.
Dielectric properties of both in-phase and anti-phase motions of polymer-dispersed antiferroelectric liquid crystals (PDAFLC) were changed because of the influence of charge density accumulated on smectic layers and its gradient variation. The elastic constant as well as dielectric parameters were changed because of the coupling between charge density variation and the physical properties of polymer constituents such as free volumes, cross-link chains. The theoretical model provides a clear influence of charge density in PDAFLC which modified the dielectric parameters, such as dielectric constant, dielectric loss, dielectric strength, etc. depending on the variation of charge density as well as polymeric parameters for both in-phase and anti-phase motions. The obtained theoretical basis is discussed by considering the results with the experimental findings and the theoretical deduced equations.
The present study is devoted to analyzing effects of high contents (85 wt.%) of dielectric inclusions, including nanocellulose and silicon dioxide nanoparticles, on ferroelectricity of composites which are made by combining dimethylammonium aluminum sulfate hexahydrate with each of them. The obtained results revealed that in the case of using nanocellulose, the ferroelectricity was not detected in fresh composite samples, but then gradually appeared over time. Meanwhile, the ferroelectricity was not observed in the composite with silicon dioxide during the observation time.
In the framework of the density functional theory electronic band structure and density of states of LaxBa1-xMnO3 solid solutions containing different concentrations of La and Ba atoms, were studied using different exchange correlation functionals. Our calculation show that the band gap, which characterizes the properties of semiconductors, varies depending on the concentration of La and Ba atoms in the compounds. Using such a dependence, it is possible to make changes in physical properties depending on the concentration of cations.
Motivated by the recently discovered superconductivity in Sr-doped nickelate oxides NdNiO2 reduced from NdNiO3 in experiments, we predict a Mott multiferroic BiNiO2 that may be obtained from BiNiO3. There is a ferroelectric structural transition for BiNiO2 from the nonpolar phase to the polar phase with the P4mm space group, which is driven by the lone pair on Bi. The lowest energy ground-state for polar BiNiO2 is a Hubbard Mott insulator with the G-type antiferromagnetic spin configurations. The replacement of Nd by Bi serves as a connecting link between a parent compound of high-temperature superconductor and a Mott multiferroic.
In this paper, a series of Sr0.96Al2Si2O8 phosphors doped with 0.02Eu(2+) and 0.02Re(3+) (where Re = Tm, Dy, Er, Nd, Sm, La, Ho) were synthesized using the high-temperature solid-phase method at 1350 degrees C for 4 hours. The samples underwent characterization for structural and phase analysis using XRD-6000. Fluorescence and photostimulated properties were evaluated with F-4600. The pyroluminescence curve indicates a trap depth of 0.6-0.8 eV for Sr0.96Al2Si2O8: 0.02Eu(2+), 0.02Re(3+) (where Re = Dy, Er, Sm, La, Ho), making it suitable for prolonged afterglow luminescence. In comparison with deep trap material Sr0.96Al2Si2O8: 0.02Eu(2+), 0.02Nd(3+), the generated traps approach or exceed 1 eV, suggesting its potential for use as a light excitation and optical storage material. Additionally, the correlation between sample TL and PSL was examined, confirming that the augmentation of initial photostimulated luminescence intensity is closely associated with the generation of new traps. Furthermore, considering the effect of different trivalent lanthanide rare earth ion doping on trap depth from a trap regulation perspective offers a potential avenue for elucidating the nuanced processes underlying photostimulated luminescence.
Abstract In this paper, we investigate the lattice thermal conductivity of Janus In2Ge2S6 and In2Ge2S3Se3 bilayers by solving the phonon Boltzmann transport equation using first-principles calculations. We found that this is mainly due to the fact that the frequencies at which larger gaps appear in the intermediate and high frequency optical branches of In2Ge2S3Se3 are smaller than those of In2Ge2S6, which shifts the phonon dispersion curve of In2Ge2S3Se3 downward, which makes the overall phonon group velocity of In2Ge2S3Se3 material smaller than that of In2Ge2Se6 material, and also due to the fact that In2Ge2S3Se3 soft bending in the finite layer thickness coupling and the tight connection of the in-plane acoustic modes, resulting in increased phonon-phonon scattering processes, shorter phonon relaxation times, and larger Grüneisen parameters indicating a stronger anharmonic In2Ge2S3Se3 structure, all these factors combined lead to a lattice thermal conductivity of In2Ge2S3Se3 smaller than the lattice thermal conductivity of In2Ge2S6. At a temperature of 1000 K, the In2Ge2S3Se3 structure has a minimum lattice thermal conductivity of about 0.22 W/mK, and In2Ge2S6 has a minimum lattice thermal conductivity of about 0.4 W/mK. Our results suggest that Janus In2Ge2S6 and In2Ge2S3Se3 bilayers are potential for future thermal management of nanoelectronic devices and thermoelectric devices. two-dimensional materials.
This paper proposes a Dual-Cylinder Piezoelectric Energy Harvester (DC-PEH). The cylinders generate vortex-induced vibration under the action of wind, driving the cantilever beam to deform. During the vibration process, the cantilever beam produces two types of bending modes, namely U-shaped vibration and S-shaped vibration. According to the experimental results, as the wind speed increases, the output power of the DC-PEH first increases and then decreases. When the diameter of the cylinders at both ends of the DC-PEH is 36 mm and the wind speed is 4.3 m/s, the output power can reach 7.812 mW.
Multiferroic ceramic composites of (Ba0.7Gd0.3MoxFe12-xO19 were prepared by using the solid-state reaction method with mol% fractions of x = 0.02, The preliminary structural studies carried out by X-ray diffraction at room temperature. It reveals that the samples have a hexagonal structure ferrite phase. The impurity phase of x-Fe2O3 appear at 32 similar to 34 degree. Debye-Scherer and Williamson-Hall method were used to analysis for peak broadening Ba0.7Gd0.3MoxFe12-xO19 (where x = 0.02). Dielectric graphs show that curie temperature shifted towards the high temperature with increasing the frequency. the dielectric transitions at 200-300 degrees C.
In this article, we examined the electromechanical behavior of Sn-substituted Lead Bismuth Zirconate Titanate thin films (PBZST thin films). Using the pulsed laser deposition technique (PLD), the thin film growth parameters of bismuth-doped PZST close to MPB were adjusted by varying the similar to(Zr, Sn)/Ti ratios. Thin films (similar to 250 nm) with the stoichiometric formula Pb0.985Bi0.01(Zr0.7Sn0.3) x Ti1 - x O3, (x = 0.935, 0.940, 0.945, and 0.950) were grown on a Pt/TiO2/SiO2/Si substrate using PLD technique at optimized conditions. P-E loop confirms that MPB is near x = 0.945, and further PFM measurements also confirmed the same. Analyzing the PFM phase and amplitude hysteresis loops, local piezo-electric coefficient and remnant strain values were computed as d33 = 330 pm/V and 0.33 at the MPB composition (x = 0.945).
In order to improve the output torque of an in-plane bending mode traveling wave rotary ultrasonic motor, a double-sided tapered teeth traveling wave rotary ultrasonic motor was proposed. The motor is designed with three types of adaptive rotors that can be used for replacement in different output environments. Simulation analysis was conducted using ANSYS, and prototype production and experimental testing were conducted. The experimental results show that when the excitation voltage is 300V and the excitation frequency is 22.665 kHz, the maximum output torque that the motor provide is 3.087 N center dot mm, and the maximum no-load speed is 295rpm.
In terms of piezoelectric class (6 mm) crystal semiconductor, the propagation of shear surface waves on the half-space surface under initial stresses is studied. The initial stresses and material parameters are hypothesized to exponentially vary along x - direction only. Besides, the velocity equations of SH waves can be obtained based on the boundary conditions and the kinematic equations of the initially stressed graded piezoelectric semiconductor material, as well as the traction-free boundary conditions. Based on the numerical results, we explore how the semiconductivity, initial stresses as well as material gradient index impact the dispersive curves.
The dielectric constant and hysteresis loops of BaTiO3 ceramics with and without Pt implants were compared to determine the effect of the implant on the ceramic behavior. Ceramics with 90% relative density and 13.28 mu m average grain size were analyzed. The results showed alterations in the ceramic's coercive field, remanent polarization, and dielectric constant with an implant. The metallic implant affected the internal structure of the BaTiO3 ceramic, which reduced the ferroelectric properties of the material. In principle, these alterations can be seen as drawbacks, but they open new applications. The results provide insights into the real impact of metallic implants on the ferroelectric properties of the samples.
In this paper, we investigate the lattice thermal conductivity of Janus In2Ge2S6 and In2Ge2S3Se3 bilayers by solving the phonon Boltzmann transport equation using first-principles calculations. We found that this is mainly due to the fact that the frequencies at which larger gaps appear in the intermediate and high frequency optical branches of In2Ge2S3Se3 are smaller than those of In2Ge2S6, which shifts the phonon dispersion curve of In2Ge2S3Se3 downward, which makes the overall phonon group velocity of In2Ge2S3Se3 material smaller than that of In2Ge2S6 material, and also due to the fact that In2Ge2S3Se3 soft bending in the finite layer thickness coupling and the tight connection of the in-plane acoustic modes, resulting in increased phonon-phonon scattering processes, shorter phonon relaxation times, and larger Gruneisen parameters indicating a stronger anharmonic In2Ge2S3Se3 structure, all these factors combined lead to a lattice thermal conductivity of In2Ge2S3Se3 smaller than the lattice thermal conductivity of In2Ge2S6. At a temperature of 1000 K, the In2Ge2S3Se3 structure has a minimum lattice thermal conductivity of about 0.22 W/mK, and In2Ge2S6 has a minimum lattice thermal conductivity of about 0.4 W/mK. Our results suggest that Janus In2Ge2S6 and In2Ge2S3Se3 bilayers are potential for future thermal management of nanoelectronic devices and thermoelectric devices. two-dimensional materials.
A 2-1-2 composite with two single-crystal components is studied for the first time to highlight large hydrostatic piezoelectric coefficients dh * and gh *, figure of merit d(h) *g(h) *, and electromechanical coupling factor k(h) *. Each 2-1-2 composite contains layers of domain-engineered [011]-poled relaxor-ferroelectric (1-x)Pb(Zn1/3Nb2/3)O-3 - xPbTiO(3) single crystal (x = 0.0475-0.09) and heterogeneous layers being systems of aligned piezoelectric Li2B4O7 single crystal rods in polyethylene, and these rods have an elliptic cylindrical shape. New diagrams show the volume-fraction ranges wherein large values of d(h) *> 10(-9 )C/N, d(h) *g(h) *> 2.10(-10) Pa-1 and k(h) *approximate to 0.5-0.6 are observed.
A trivalent rare earth ion Holmium doped zinc magnesium lithium fluoroborate (ZMLB) glasses with the composition of 10ZnO-10MgO-20LiF-(60-x)B2O3-xHo(2)O(3) (where x = 0, 0.1, 0.3, 0.5 and 1 mol%) were prepared by a well-known melt quenching procedure. The produced glass samples structural, optical, emission and decay curve characteristics have been investigated. From the X-ray diffraction investigation, it is confirmed all the produced glasses possess amorphous nature. The borate-oxygen and vibration bonds were noticed by using Fourier transform infrared analysis. From the ultraviolet-visible absorption studies, the produced glasses absorption peaks were noticed and optical energy band gap values also identified by using Tauc's relation. Under excitation with 456 nm, the Ho3+ activated ZMLB glasses luminescence spectra consist of three luminescence bands positioned at 550, 677 and 764 nm were corresponding electronic transitions are S-5(2) + F-5(4) -> I-5(8), F-5(5)-> I-5(8) and F-5(4)-> I-5(7), respectively. From all these emission bands the prominent emission band observed at 550 nm (green). For the Ho3+ activated ZMLB glasses, the lifetimes were decreased with the enhance of Ho3+ doping content owing to energy transfer in resonance form in between Ho3+ ions. From emission spectra, the CCT and CIE coordinates were estimated, and the CIE values are pointed greenish-yellow area in CIE image. Therefore, all these findings convey that the current zinc magnesium lithium fluoroborate glasses conceivably significant candidate for green display and lighting applications.
