X-ray Peak Research Articles

Study of a Compton backscattering wall defects detection device using the Monte Carlo method

Abstract In view of the shortcomings of traditional wall defect detection methods, such as small detection range, poor accuracy, non-portable device, and so on, a wall defects detection device based on Compton backscattering technology is designed by Monte Carlo method, which is mainly used to detect the size and location information of defects in concrete walls. It mainly consists of two parts, the source container and the detection system: first, through the simulation and analysis of the parameters such as the receiving angle of the backscattered particles and the rear collimating material of the detector, the influence of the fluorescent X-ray peak of the detector collimating material on the backscattered particle counts is eliminated and the detected error is reduced; second, the ring array detector design, compared with single array detector and surface array detector, can facilitate real-time detection of defect orientation, expanding the single scan range and improving the detection efficiency. After simulation and comparative analysis, the relevant optimal parameters are obtained: the object is detected using a Cs-137 γ-ray source with an activity of 6 mCi, and a ring detector consisting of four 0.5-inch cube-shaped CsI scintillator detectors is placed at 150° to receive the backscattered photons. The simulation analysis using the Monte Carlo FLUKA program showed that the maximum depth of wall defect detection is 8 cm, the maximum error fluctuation range of defect depth and thickness is ±1 cm, the overall device weight is <20 kg, and the measurement time is <5 min.

Rational synthesis of alkaline earth metal vanadates: Structural origin of MgVO3 honeycomb lattice system and its electrochemical analysis for the detection of sulfadiazine

In this study, well-defined alkaline earth metal vanadates, including MgV, CaV, SrV, and BaV, are synthesized using a simple hydrothermal method, and the crystalline structure, morphology, and structural parameters of the synthesized alkaline earth metal vanadates are investigated and compared. Among the alkaline earth metal vanadates, the MgV shows the unique 3D architecture and MgVO3 hexagonal phase with space group R-3c (167) and a single crystalline phase in V4+ valence state and Mg2+ state revealing cation dimerization in 3d1 honeycomb system. Further Raman spectroscopy with Lorentzian peak fitting and X-ray photoelectron spectroscopy exhibit the phase development with a bucky-ball structure. In order to apply the unique feature, the MgV based composite with reduced graphene oxide as a co-catalyst is prepared to examine the practical application for electrochemical sensing of sulfadiazine. The differential pulse voltammetry and the amperometry i-t analysis demonstrate the superior performance of MgV/reduced graphene oxide composite for the sulfadiazine detection including a superior low limit of detection of 9 nM from the differential pulse voltammetry measurements and 3 nM from the amperometry i-t analysis as well as excellent selectivity and long-term stability. These results are attributed to the enhanced electron transfer and ion diffusion from the synergistic effect of unique MgV and reduced graphene oxide. Moreover, the MgV/reduced graphene oxide composite delivers excellent capability in the detection of sulfadiazine in real samples of human blood serum, industrial wastewater, and pharmaceutical tablet.

Application of spectrum smoothing to improve the accuracy of atomic inner-shell ionization cross sections impacted by electron near the threshold energy

In this study, the X-ray spectrum smoothing is applied to improve the reading precision of the experimental X-ray peak net counts. The experimental Sn L-shell X-ray production cross sections (XRPCSs) and Bi-Mαβ XRPCSs before and after smoothing are compared, respectively. The result shows that spectrum smoothing effectively improves the accuracy of the experimental XRPCSs. The after-smoothing present XRPCSs agree well with the distorted wave Born approximation (DWBA) theoretical XRPCSs and are consistent with the previously published XRPCSs within the experimental uncertainty. Finally, the factors affecting the comparison between the experimental and DWBA theoretical XRPCSs are analyzed.

Revisiting empirical solar energetic particle scaling relations

Aims. The possible influence of solar superflares on the near-Earth space radiation environment are assessed through the investigation of scaling laws between the peak proton flux and fluence of solar energetic particle (SEP) events with the solar flare soft X-ray peak photon flux. Methods. We compiled a catalog of 65 well-connected (W20-90) SEP events during the last three solar cycles covering a period of ∼34 yr (1984–2020) that were associated with flares of class ≥C6.0, and investigated the statistical relations between the recorded peak proton fluxes (IP) and the fluences (FP) at a set of integral energies from E > 10, > 30, and > 60 to > 100 MeV versus the associated solar flare peak soft X-ray flux in the 1–8 Å band (FSXR). Based on the inferred relations, we calculated the integrated energy dependence of the peak proton flux (IP) and fluence (FP) of the SEP events, assuming that they follow an inverse power law with respect to energy. Finally, we made use of simple physical assumptions, combining our derived scaling laws, and estimated the upper limits for IP and FP focusing on the flare associated with the strongest ground level enhancement (GLE) directly observed to date (GLE 05 on 23 February 1956), and that inferred for the cosmogenic radionuclide-based SEP event of AD774/775. Results. A scaling law relating IP and FP to the solar soft X-ray peak intensity (FSXR) as ∝ $ {F}_{\mathrm{SXR}}^{5/6} $ for a flare with a FSXR = X600 (in the revised scale) is consistent with values of FP inferred for the cosmogenic nuclide event of AD774/775.

Correlating properties of alloys with constituent phases and their Raman spectra

Microstructure in alloys decides their physical properties; however, microstructure variations in metallic alloys are never quantitative. This applies to ferrous and non-ferrous alloys. Therefore, a correlative methodology is proposed for their indirect quantification using x-ray diffraction (XRD) and Raman spectroscopy. As a representative case, 16 different iron-based alloys with slight variations in composition and microstructure are considered. Changes to their properties and microstructure are correlated with XRD and Raman spectroscopy. Thermal treatments also have a role in such variation. Every x-ray peak position and FWHM was analyzed and correlated with corresponding Raman spectra and FWHM. The objective is the development of a reliable database and secondary testing methodology for fast performance estimation of different ferrous and non-ferrous alloys during production and for checking repeatability, other than by their microstructure and tensile strength, which is done at present.

Criteria for Dynamical Timescale Mass Transfer of Metal-poor Intermediate-mass Stars

The stability criteria of rapid mass transfer and common-envelope evolution are fundamental in binary star evolution. They determine the mass, mass ratio, and orbital distribution of many important systems, such as X-ray binaries, type Ia supernovae, and merging gravitational-wave sources. We use our adiabatic mass-loss model to systematically survey intermediate-mass (IM) stars’ thresholds for dynamical timescale mass transfer. The impact of metallicity on the stellar responses and critical mass ratios is explored. Both tables (Z = 0.001) and fitting formulae (Z = 0.001 and Z = 0.02) of the critical mass ratios of IM stars are provided. An application of our results to intermediate-mass X-ray binaries (IMXBs) is discussed. We find that the predicted upper limit to mass ratios, as a function of orbital period, is consistent with the observed IMXBs that undergo thermal or nuclear timescale mass transfer. According to the observed peak X-ray luminosity, L X, we predict the range of L X for IMXBs as a function of the donor mass and the mass-transfer timescale.

Characteristics of X-class flares of solar cycles 23 and 24 in X-ray and EUV bands

The characteristics of X-class flares of solar cycles 23 and 24 are examined based on the soft X-ray (0.1–0.8 nm) and EUV (26–34 nm) light curves. First, the commonly used correction factors for the center-to-limb variation of EUV flux are compared. Subsequently, enhancements in X-ray and EUV levels are used to calculate the relative apportionment of flare energy released in these two bands. The X-ray to EUV proportion of energy is found to be larger in the high X-class flares (X9.0 and stronger) as compared to the flares weaker than X9.0. The X-ray and EUV light curves revealed that the time of impulsive and thermal EUV peaks differed from X-ray peak by ∼0–25 min. The time differences had a broad range for weaker flares but reduced to within ∼7 min for high X-class flare events. Therefore, the present study brings out the general energetics and temporal evolution of phases of the X-class flares. Implications of the findings on solar flare studies and flare impact on terrestrial atmosphere are discussed.

Effect of metal ions on structural, morphological and optical properties of nano-crystallite spinel cobalt-aluminate (CoAl2O4)

The bright blue nano crystallite cobalt aluminate (CoAl2O4) was synthesized by sol–gel method using a mixture of chelating agent of glycerol and citric acid. The effects of changing (0.05, 0.075, 0.10, 0.25, 0.50, and 0.75 mol/L) metal ion concentration on the structural, morphological and color properties of synthesized CoAl2O4 were characterized by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Nanoparticle size analyzer, Simultaneous Thermal Analyzer (STA), UV–vis absorption spectroscopy, and CIE-LAB colorimetric analysis. From the X-ray peak profile analysis, the crystallite size was measured by Debye-Scherrer (D-S) equation, and three different models presenting average crystallite sizes between 88.3 and 125.4 nm.The average lattice strain, dislocation density, lattice constant, cell volume, and zeta potential were between 0.00021 and 0.0058, (1.73 to 12.8) × 1014 (lines/m2), 8.10658 to 8.11181 Å, 533.60 to 533.81 Å3, −56.4 to − 63.5 mV, respectively. Using UV–vis absorption spectroscopy, the band gap was calculated from Kubelka-Munk method, and the values of band gap increasing from 1.82 to 1.84 eV, respectively. The reflectance spectra and the CIE-L*a*b* values of cobalt aluminate is also measured which confirmed the formation of blue nano crystallite cobalt aluminate.

A miniature filamentless X-ray tube for the on-board calibration of space-borne X-ray detectors

The on-orbit calibration of the space X-ray detectors is important to obtain the accurate science data. Radioactive isotopes such as 241Am and 55Fe are generally used to implement calibration for space X-ray mission. However, the radioactive source is potential risk for the health safety and also causes a persistent radiation background during X-ray detector operation in space. On-orbit calibration of X-ray detectors has always been a difficult problem for space missions. This paper presents a miniature filamentless X-ray tube (MFXT) with tungsten target which can be used to calibrate X-ray detector on-orbit. At −12 kV high-voltage applied on MFXT, the strong L-series of characteristic X-ray of tungsten target is produced, so the gain and offset parameters of detector can be easily determined by the energy peaks of characteristic X-rays of tungsten. And after about 24 h of cumulative experiment, at least two characteristic ray peaks that can be used for calibration are formed with 5 minutes cumulative time after turning on it again with 5.2E+3 counts/s/sr radiation intensity by MFXT. As of the miniature, low power consumption and high reliability, this MFXT is an alternative to replace the radioactive source for on-orbit detector calibration in space missions.

Evolution of Magnetic Fields and Energy Release Processes during Homologous Eruptive Flares

We explore the processes of the repetitive buildup and the explosive release of magnetic energy, together with the formation of magnetic flux ropes, which eventually resulted in three homologous eruptive flares of successively increasing intensities (i.e., M2.0, M2.6, and X1.0). The flares originated from NOAA active region 12017 between 2014 March 28 and 29. EUV observations and magnetogram measurements, together with coronal magnetic field modeling, suggest that the flares were triggered by the eruption of flux ropes that were embedded in a densely packed system of loops within a small part of the active region. In X-rays, the first and second events show similar evolutions, with single compact sources, while the third event exhibits multiple emission centroids, with a set of strong nonthermal conjugate sources at 50–100 keV during the hard X-ray peak. Over an interval of ≈ 44 hr, the photospheric magnetic field encompassing the three flares undergoes important phases of emergence and cancellation, together with significant changes near the polarity inversion lines within the flaring region. Our observations point toward the tether-cutting mechanism being the plausible triggering process of the eruptions. Between the second and third events, we observe a prominent phase of flux emergence that temporally correlates with the buildup phase of free magnetic energy in the active region corona. In conclusion, our analysis reveals efficient coupling between the rapidly evolving photospheric and coronal magnetic fields in the active region, leading to a continued phase of the buildup of free energy, which results in the homologous flares of successively increasing intensities.

The eROSITA Final Equatorial-Depth Survey (eFEDS)

Context.We present the results of a systematic X-ray analysis of optically rich galaxy clusters detected by the Subaru Hyper Suprime-Cam (HSC) survey in the eROSITA Final Equatorial-Depth Survey (eFEDS) field.Aims.Through a joint analysis of the SRG (Spectrum Roentgen Gamma)/eROSITA and Subaru/HSC surveys, we aim to investigate the dynamical status of the optically selected clusters and to derive the cluster scaling relations.Methods.The sample consists of 43 optically selected galaxy clusters with a richness >40 in the redshift range of 0.16–0.89. We systematically analyzed the X-ray images and emission spectra using the eROSITA data. We identified the brightest cluster galaxy (BCG) using the optical and far-infrared databases. We evaluated the cluster’s dynamical status by measuring three quantities: offset between the X-ray peak and BCG position, the gas concentration parameter, and the number of galaxy-density peaks. We investigated the luminosity–temperature and mass–luminosity relations based on eROSITA X-ray spectra and HSC weak-lensing data analyses.Results.Based on these three measurements, we estimated the fraction of relaxed clusters to be 2(< 39)%, which is smaller than that of the X-ray-selected cluster samples. After correcting for a selection bias due to the richness cut, we obtained a shallowL−Tslope of 2.1 ± 0.5, which is consistent with the predictions of the self-similar model and the baseline model incorporating a mass–concentration relation. TheL−Mslope of 1.5 ± 0.3 is in agreement with the above-cited theoretical models as well as the data on the shear-selected clusters in the eFEDs field.Conclusions.Our analysis of high-richness optical clusters yields a small fraction of relaxed clusters and a shallow slope for the luminosity–temperature relation. This suggests that the average X-ray properties of the optical clusters are likely to be different from those observed in the X-ray samples. Thus, the joint eROSITA and HSC observations are a powerful tool in extending the analysis to a larger sample and understanding the selection effect with a view to establish cluster scaling relations.

Optimization, Characterization, and Biological Applications of Silver Nanoparticles Synthesized Using Essential Oil of Aerial Part of Laggera tomentosa

Biological synthesis of silver nanoparticles (AgNPs) is a green, simple, cost-effective, time-efficient, and single-step method. This study mainly focused on the synthesis of silver nanoparticles (AgNPs) using essential oil of Laggera tomentosa (LTEO) and investigates their potential applications. Ultraviolet-Visible (UV-Vis) result showed the characteristic Surface Plasmon Resonance (SPR) peak of LTEO-AgNPs at 420 nm. Fourier transform infrared (FT-IR) spectroscopy indicated the functional groups present in LTEO and LTEO-AgNPs. Scanning electron microscope (SEM) image depicted the synthesized AgNPs mainly has spherical shapes with average nanoparticles size 89.59 ± 5.14 nm. Energy dispersive X-ray (EDX) peak at 3.0 keV showed the presence of Ag element in LTEO-AgNPs. The X-ray diffraction (XRD) peaks at 38°, 44° and 67° are assigned to (111), (200), and (220), respectively which displays the crystal nature of LTEO-AgNPs. The average particle size and zeta potential of LTEO-AgNPs were determined as 94.98 nm and −49.6 mV, respectively. LTEO-AgNPs were stable for six months against aggregation at room temperature. LTEO-AgNPs solutions exhibited potential activities for the treatment of some pathogenic bacteria species, agricultural productivity growth, determination of metallic ions, and catalytic reduction. This study is the first work to report nanoparticles synthesis using L. tomentosa extracts and evaluate their potential applications.

Zn-based MOFs materials fabricated by mechanochemical ball milling and hydrothermal method and derived metal oxides

In the present work, the Zn-MOFs nanostructures from zinc sulfate and cyanoguanidine source precursors were successfully fabricated through two chemical and mechanical synthesis methods including hydrothermal and high energy ball milling methods. Then, the obtained Zn-MOFs were calcined at 550 °C for 110 min. The prepared nanostructures were determined by XRD, SEM and FTIR methods to gain insight about structure, morphology and functional groups properties. The findings confirm the fabrication of Zn-MOFs by using high energy ball milling methods. In addition, the obtained MOF and complex structures can be converted to porous zinc oxide by a simple thermal annealing in air. Then, the line broadening of ZnO calcined at 550 °C from MOFs structures from mechanochemical and hydrothermal methods due to the small crystallite size and lattice strain. The X-ray peak broadening analysis was investigated by the Scherrer formula and Williamson Hall method including uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM) and size-strain plot method.

Influence of Cu induced crystallographic disorder on the optical and lattice vibrational properties of ZnO nanoparticles.

In this study, the vibrational and optical responses of 0-10% excess Cu incorporated ZnO nanoparticles (NPs) prepared by the low temperature (∼400 °C) wet chemical route were investigated experimentally and were found to be predominantly linked to the formation of both intrinsic and Cu induced crystallographic defects instead of substitutional Cu itself for the first time. For low temperature chemical synthesis, the effective band gap (Eg) of pristine ZnO NPs was found to be as low as 2.84 eV, which was followed by a further reduction by as high as ∼24.4% with gradual Cu inclusion. Excess Cu incorporation was found to drastically restrict the particle growth phenomenon by ∼61% and alter the shape morphology from anisotropic to irregular isotropic. Although all NPs showed a single phase structure with hexagonal P63mc symmetry, the X-ray peak profile analysis along with the characteristic E2(High) Raman peak and electron-phonon coupling strength obtained from the 2nd order Raman mode suggested the presence of appreciable crystallographic disorders pertaining to point defects like Cu induced Zn and O interstitials and vacancies. Optical analysis revealed a gradual increase in Urbach tailing (Eu) from 0.35 to 0.96 eV directly associated with both intrinsic and Cu induced disorders arising from successive Cu incorporation at low processing temperature. A correlation between Eg and Eu predicted a direct-type band-to-band transition energy of ∼3.2 eV for the pristine ZnO crystal, suggesting both intrinsic and excess Cu induced extrinsic disorders to be the primary source of optical modulation of the NPs for the low temperature processing condition.

Synchrotron self-compton emission in the two-component jet model for gamma-ray bursts

Gamma-ray bursts (GRBs) are intense bursts of high-energy photons (prompt emissions) caused by relativistic jets. After the emissions, multi-wavelength afterglows, from radio to very-high-energy (VHE) gamma-ray, last for more than a few days. In the past three years, the VHE gamma-ray photons from four GRBs (GRBs 180720B, 190114C, 190829A and 201216C) were detected by ground-based Imaging Atmospheric Cherenkov Telescopes, such as the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes and the High Energy Stereoscopic System (H.E.S.S.). One of them, GRB 190829A, had some peculiar features of showing achromatic peaks in X-ray and optical bands at 1.4×103 s and being classified as low-luminosity GRBs. Previously, we proposed a two-component jet model, which has ‘narrow jet’ with a small initial opening half-angle θ0=0.015 rad and large bulk Lorentz factor Γ0=350, and ‘wide jet’ with θ0=0.1 rad and Γ0=20. The narrow jet explained the early X-ray and optical emissions and apparently small isotropic gamma-ray energy and peak energy in the off-axis viewing case. Furthermore, the late X-ray and radio (1.3 and 15.5 GHz) afterglows were emitted from the wide jet. Here, we calculate the VHE gamma-ray flux by the synchrotron self-Compton (SSC) emission. The multi-wavelength afterglows of GRB 190829A including the VHE gamma-ray emission are well explained by our two-component jet model. The afterglow emissions from our two-component jet are also consistent with the observational results of GRBs 180720B, 190114C and 201216C, when the jets are viewed on-axis. Furthermore, we discuss the detectability of off-axis orphan afterglows by the Cherenkov Telescope Array (CTA).

Microstructure characterization of polycrystalline yttrium iron garnets (YIGs) sintered from the calcined sol-gel powder

We present the results of microstructural characterization of the polycrystalline yttrium iron garnet (YIG) during high temperature sintering. Three YIG samples, compacted from the calcined sol-gel powder, are annealed at 1400 °C for 350 min, 1050 min and 1750 min, respectively. During the annealing, the polycrystalline YIG coarsens via normal grain growth, developing self-similar steady-states in grain size distribution, grain texture, and grain boundary texture. However, the 1050-min and 1750-min samples feature x-ray peaks with narrower full width at half-maximum (FWHM), and smaller local misorientation than the 350-min one, signifying that the strain still decreases after annealing for 350 min at 1400 °C. EPMA analyses show that more uniform distribution of the elements is found in 1750-min sample than in 350-min sample. Notably, little segregation of metal elements is observed on the grain boundary of the current YIG samples, as opposed to previously reported conventionally sintered YIGs using yttrium-oxide and iron-oxide powders, often featuring either second phases or segregation of Fe on YIG grain boundaries. • The high-density polycrystalline yttrium iron garnet (YIG) is sintered using calcined sol-gel powders. • Microstructure coarsens via normal grain growth, maintaining the self-similarity in grain size distribution, grain texture, and grain boundary misorientation and texture. • X-ray and KAM measurements suggest that the lattice strain reduces during annealing. • Considering observed slow growth kinetics, both sharpening of the X-ray peaks and decrease in the KAM may result from the homogenization of elements during annealing, producing the concurrent reduction in the lattice strain.

Simulations about Stability, Damage, and Heating Impacts for an X-ray Optical Delay Line at SASE3

European XFEL has initiated a project to facilitate two-color pump-probe spectroscopy with X-rays at the SASE3 soft X-ray undulator. To this end, the controllable temporal delay between the two X-ray pulses is obtained by a magnetic chicane and an optical delay line (ODL) that delay the electron and X-ray beams, respectively. This article focuses on describing the alignment process of the ODL and its related specification. The distance between the experimental station and the ODL is nearly 500 m, thus if one of the mirrors in the ODL is misaligned, the focus spot experiences a noticeable shift. Moreover, a pulse train can include up to 2700 X-ray pulses with a minimum spacing of 222 ns. An increase in temperature per pulse would just add up if there was no heat removal during that time and the material could be damaged during a pulse train. The question arises whether the X-ray optics can survive the high X-ray peak power during a single pulse. Finally, the present study also investigates the damage issue.

A comparative study on X-ray peak broadening analysis of mechanically alloyed Al2O3 particles dispersion strengthened Al 7017 alloy

AA7017 + x vol. % Al2O3 (x = 5, 10, 20) nanocomposites powders were synthesized by HEBM process with milling time of 0 h and 20 h. The synthesized nanocomposite powders were characterized using XRD (Bruker USA D8 Advance, Davinci) with CuKα (1.5406 Aͦ), 2θ range (30°-90°), and Scan Speed (1°/min) for examining the crystalline nature of the powder samples. The size and shape of the powder particle were identified by HR-SEM (FEI Quanta FEG 200F) with 30 KV voltage, wide magnification range (12x-105 x) and secondary electron mode, and HR-TEM (JEOL Japan, JEM-2100 Plus) with voltage (200 kV), and magnification range (below 50 nm). Powder particles were measured by laser scattering technique using zeta analyzer (Laser Particle size Analyser, M/s Microtrac),and finally, the melting point and peak shift variation of composite powder samples were analyzed using TG-DSC (Netzsch TG-DSC) with temperature range (25–1400 °C), and heating rate (10 °C/min)under argon atmosphere. Furthermore, the particle sizes evaluated from different models of diffraction analysis (Scherrer, Williamson-Hall, and size-strain plot, SSP, methods) were compared with the results from PSA, HR-SEM, and HR-TEM analyses. The obtained mechanical properties explained that 20h milled AA7017 + x vol. % Al2O3 (x = 5, 10, and 20) samples produced higher values; and the properties improvement in all the samples were correlated theoretically by various strengthening mechanisms.

The influence of l-ornithine monohydrochloride on growth and various properties of ammonium dihydrogen phosphate crystals

In the present work, an aim is to investigate the influence of l-Ornithine monohydrochloride (LOMHCl) doping on structural, optical and electrical properties of pure ADP crystals. It is analyzed by following various characterizations. Pure and LOMHCl doped ammonium dihydrogen phosphate (ADP) crystals have been grown by using slow solvent evaporation technique at room temperature in dust free laboratory. The powder XRD patterns show the single phase nature of pure and doped ADP crystals. The average crystallite size and strain are found from X-ray peak broadening analysis. The UV–Vis spectra indicate slight decrement in the transmittance and band gap values of doped ADP crystals. The SHG efficiency of doped ADP crystals found to increase compared to pure ADP and pure KDP. Z-scan analysis shows increased nonlinear optical properties of doped ADP crystals. The dielectric constant and loss plots show usual behavior with respect to frequency and reduction in the values of doped ADP. The Jonscher's power is studied for ac conductivity. The complex impedance and modulus plots show single semicircle for both pure and doped ADP due to grain contribution only. The stretch exponent parameter values indicate the non-Debye type relaxation process.

Giant effect on structural, magnetic, electrical, and optical properties of lead-free Ba0.6Sr0.4Ti1-xAlxO3 ceramics via Sr and Al Co-doping engineering

In this research, structural, magnetic, electrical, and optical properties of Al 3+ substituted Ba0.6Sr0.4Ti1-xAlxO3 ceramics (where x = 0.00 to 0.20) have been investigated and discussed. The ceramic samples have been successfully synthesized by the conventional solid-state reaction method. The crystallinity of the prepared samples has been confirmed by x-ray peak broadening techniques such as the Williamson Hall (W-H) plot technique and the Scherrer method. The lattice constant ‘a’, showing a significant drop as Al concentration increases, varies from 3.942 Å to 3.921 Å. The FTIR spectrum revealed a prominent peak between 435 cm−1 to 540 cm−1, without showing any secondary phase. Raman spectroscopic analysis showed that the prepared samples are in cubic phase with no phase transition. The shifting of a dominating peak in Raman at 580 cm−1 is due to the development of Al Ti defects. VSM analysis at room temperature showed the ferromagnetic characteristics of all the samples. The highest value of the anisotropic constant (Ka ∼ 39.933 emu cm−3) has been seen at x = 0.10. The real component of initial permeability is almost constant for the frequency range of about 75 MHz, and above this frequency range, it quickly reduces. At the high-frequency range, the prepared samples show an excellent relative quality factor due to the low dielectric loss, notably when x = 0.05. The prepared perovskites exhibited minimum eddy current loss characteristics due to the increment of AC resistivity at x = 0.20. UV–visible spectroscopy shows a significant change in the energy bandgap from 3.23 eV to 3.04 eV with the doping concentrations.