Solid-state Reaction Method Research Articles

Tailoring Bi1−x−yBaxFeyFeO3 for desired properties: insights into structural, dielectric, and magnetic responses

In present study, samples of Bi1−x−yBaxFeyFeO3 have been synthesized, where x = 0.15, y = 0; x = 0.10, y = 0.10; and x = 0.15, y = 0.10 utilizing a swift two-stage solid-state reaction method. X-ray diffraction (XRD) data has been Rietveld refined to evaluate the structural parameters. Micro-strain is also calculated using Williamson Hall method. Temperature (300 K to 660 K) dependent measurements of the dielectric constant have been conducted at various frequencies (100 kHz, 500 kHz, and 1000 kHz). The dielectric constant (ε′) rises as the temperature increases. Two dielectric anomalies around 450 K and 613 K have been noticed in ε′ versus T curves for all the samples which might be related with defect dipoles and the magnetic transition respectively. Further, an insignificant value of loss tangent (0.2) specifically at around 300 K is a signal of small leakage current in the samples. The source of high dielectric constant is discussed by considering the structural distortions in the ceramics. A clear hysteresis loop has been observed for all the samples which is a sign of collapse of antiferromagnetic nature of BiFeO3. Further, in case of co-doped samples, almost a saturation in magnetization with magnetization value 5.9718 emu g−1 has been noticed in hysteresis curve indicating a major contribution of ferromagnetic interaction. Enhancement in the net magnetization is briefly discussed by considering the ferromagnetic type direct interaction among Fe3+ ions and suppressing the anti-ferromagnetic type super exchange interaction.

Exploring bismuth-substituted yttrium iron garnet: Insights into structural, optical, and dielectric characteristics

Magnetic garnets, a diverse group of magnetic insulating materials, have been the subject of extensive research for decades, owing to their versatility and potential for a wide range of applications. In this study, we synthesized Bismuth-Substituted Yttrium Iron Garnet (BiY2Fe5O12: BiYIG) using the solid-state reaction method to explore its structural, optical, and dielectric characteristics. X-ray diffraction analysis revealed the attainment of a pure cubic garnet phase in BiYIG, with a lattice parameter of 12.444 Å. Using UV–visible spectroscopy, we determined that the optical band gap of BiYIG is 2.2 eV, indicating n-type semiconductor behavior. We conducted a thorough investigation of the dielectric properties, examining capacitance, dielectric constant, dielectric loss, conductivity, impedance, and modulus, as functions of frequency and temperature. The impedance results revealed that the dielectric relaxation at room temperature was dominated by a Debye-type process, with a shift to a non-Debye-type process becoming apparent as temperature increased. Comprehensive analysis sheds light on the material's transport phenomena and optical attributes, offering insights into the potential of BiYIG for applications in magneto-dielectric and magneto-optical domains, given its high dielectric constant with low dielectric loss, and promising optical properties. These findings position BiYIG as a versatile material and underscore its suitability for advanced applications in future technological developments.

Effect of Co doped BCT on structural, microstructural, dielectric, and multiferroic properties

The structural, microstructural, dielectric, optical, ferroelectric, and magnetic properties of cobalt doped barium calcium titanate (BCT) (Ba0.80Ca0.20Ti1-xCoxO3 with x = 0.000, 0.005, 0.010, 0.015, and 0.020) ceramics have been reported in this paper. The ceramic samples were prepared by the conventional solid-state reaction method. For all of the prepared samples, the tetragonal structure with the space group P4mm has been confirmed using the refinement method through Rietveld refinement of X-ray diffraction patterns. Field Emission Scanning Electron Microscopy (FESEM) micrographs revealed that the average particle size exists in micrometre range (0.3–0.8) μm. Optical studies revealed a gradual decrease in the energy bandgap from 3.31 eV to 2.71 eV with increasing doping concentration. A decreasing trend was observed in the dielectric characteristics of the material with changing frequencies at room temperature. Ferroelectric (P-E loops) analysis displayed an increase in both remnant polarization and maximum polarization of the ceramic with the increasing applied electric field. The highest value for the energy storage efficiency (η) was calculated to be 20.51 %. Magnetic analysis conducted at room temperature revealed the enhancement in ferromagnetism with the increase in doping concentration.

Fabrication of innovative ZnCo2O4/Ti3C2Tx MXene nanocomposite counter electrode to replace Pt in dye-sensitized solar cells and improve solar cell performance

This study focuses on the fabrication and optimization of Ti3C2Tx/ZnCo2O4 (ZCO) hybrid counter electrodes (CEs) for Dye-Sensitized Solar Cells (DSSCs). The Ti3C2Tx Max phase was initially prepared through a solid-state reaction method and subsequently transformed into the MXene phase using the minimally intensive layer delamination (MILD) technique. ZnCo2O4 was synthesized via the sol-gel method. Various analyses, including FESEM, XRD, EDS, CV, Tafel, XPS, IPCE, and HRTEM, were employed to characterize the prepared materials. The key parameter investigated involved CEs with different weight ratios of Ti3C2Tx to ZnCo2O4 (0 %, 20 %, 30 %, and 40 %). Results revealed that the optimized DSSC with 30 % Ti3C2Tx to ZCO exhibited a remarkable efficiency of 8.61 %, surpassing both the cell without MXene (5.59 % efficiency) and the one with a Pt CE (8.12 % efficiency). The enhanced performance was attributed to a significant increase in current density primarily driven by the higher electrocatalytic activity of the ZM30 CE and improved conductivity.

Structural evolution, ferroelectric phase transitions, and dielectric behavior of Sn-doped Ba0.95Sr0.05TiO3 ferroelectric ceramics

ABSTRACT In this report, I studied the structural, morphological, and dielectric properties of new ferroelectric compounds prepared according to the formula Ba0.95Sr0.05Ti1-ySnyO3. The solid-state reaction method enhanced by a high-efficiency metal ball mill was used in the preparation process. The quantitative and qualitative analysis of the XRD patterns confirmed the crystallization of the samples y = 0.00, 0.05 in the tetragonal crystal system and the presence of the tetragonal and cubic crystal systems together in the samples y = 0.10, 0.14. Formation of BaSnO3 impurities in very low percentages in the doped samples. Their prevalence increases with increasing tin content, reaching 8.7% at the ratio y = 0.14. SEM images of the ceramic samples showed the formation of nano-ceramics with a high degree of condensation at the doping ratio y = 0.05. The dielectric analyses showed high thermal stability in the dielectric properties of the ceramic samples y = 0.05, 0.10, which was shown by the flatness of the dielectric constant curve over the entire temperature range studied, where this stability is attributed to the structure of the nano-grains that resist the ferroelectric-paraelectric phase transition. Furthermore, the dielectric properties were interpreted by accurately linking the dielectric measurements with the nano-structural and polar properties.

Mixed proton and oxide ion conduction, phase stability, and conducting mechanisms in the Sr2CeO4-based materials

Sr2CeO4 possesses structural characteristic of one-dimensional (1D) edge-sharing CeO6 octahedral chains, exhibits superior phase and chemical stability compared to the perovskite SrCeO3. There have been previous attempts to improve electrical conductivity through proton conduction by acceptor-doping of Yb on the Ce site. However, its electrical conductivity remained low, for instance, at 500 °C, the reported value was 3.16 × 10−7 S/cm, hence limiting its practical applications. In this paper, we synthesized four new rare earth doped Sr2Ce0.95M0.05O3.975 (where M = Y, Dy, Er, Tb) by the solid state reaction method. We thoroughly investigated their phases, electrical properties, and stability. Additionally, for the first time, we investigated the proton and oxide ion conduction mechanisms in Sr2CeO4-based materials using a bond-valence-based method. This analysis revealed a clear 1D conduction along the c-axis within the CeO6 tetrahedral chains and 2D conduction within the a-c plane, respectively. The findings revealed that all doped materials showed obvious proton conduction, alongside partial oxide ion conduction. Notably, the Er-, Dy-, and Y-doped samples demonstrated significantly improved conductivity under wet condition (with a water partial pressure of ∼0.03 atm) at 500 °C, reaching approximately ∼ 10−4 S/cm. This is nearly three orders of magnitude higher than the previously reported Yb-doped Sr2CeO4.

Synthesis and characterization of Eu3Ba5Cu8O18-δ superconductor doped with 0.1% Graphene oxide

This research presents the synthesis and evaluation of the structural and morphological properties of superconducting Eu3Ba5Cu8O18-δ doped with 0.1% graphene oxide, using the solid state reaction method. The structural analysis performed on the samples, both doped and undoped, allowed identifying the main phase as Eu3Ba5Cu8O18-δ (Eu358), with orthorhombic structure and space group Pmm2(25), maintaining superconducting properties in both cases. In addition, it was observed that doping with graphene oxide resulted in the formation of a minority phase of EuBa4Cu3O9 (Eu143), with cubic structure and space group P23(195). As for the morphological characterization, it was evidenced that the undoped sample presents aggregates formed by non-uniform size grains, with an average size of approximately 97 µm. In contrast, the sample doped with 0.1% graphene oxide exhibits significant improvements in uniformity and grain boundaries, with an average size of about 141 µm. These results confirm obtaining Eu3Ba5Cu8O18-δ with a 73% superconducting phase, exceeding the percentages previously reported using the solid-state reaction method.

Efficient recovery of lithium from spent lithium-ion battery raffinate by Mn and Al-based adsorbents: pretreatment, adsorption mechanism, and performance comparison

As a strong wave of retired lithium-ion battery approaches, lithium extraction from spent lithium-ion battery raffinate (SLR) becomes increasingly critical for environmental protection and for sustainable lithium supply. To understand the factors that affect maximum recovery of lithium from SLR, the organic and inorganic components of SLR were initially determined. The organic matter content (up to 760.5 mg/L) seriously impacted the recovery rate of lithium. Therefore, SLR was managed with a series of pretreatment techniques, including coagulation, biochar aerogel adsorption, and ultrafiltration, achieving more than 84.3% removal of organic substances. H1.33Mn1.67O4 and Li/Al layered double hydroxides adsorbents were then synthesized by solid state reaction method and hydrothermal method, respectively, granulated into spheres with a PVC skeleton, and applied to recycle lithium from pretreated SLR in a fixed bed adsorption column. The results indicated that both Mn and Al-based adsorbents exhibited rapid adsorption kinetics, reaching saturation within 2 h. The Mn-based adsorbent exhibited superior adsorption selectivity for Li+ and higher Li+/Na+ separation factor (αNaLi) compared to Al-based adsorbent, with partition coefficients and αNaLi values equal to 6.62 mL/g, 8.79 for the former material, and 4.92 mL/g, 8.17 for the latter. On the other hand, the Al-based adsorbent displayed better stability with negligible Al loss, while Mn loss from the related adsorbent was less than 0.2% in every adsorption–desorption cycle. Notably, both adsorbents demonstrated excellent reusability with their adsorption capacity maintained after twenty adsorption–desorption cycles.

Effects of Zn2+ substitution on the dielectric properties, chemical bonding properties, and crystal structure of Mg3(PO4)2 ceramics

A series of (Mg1-xZnx)3(PO4)2 (x = 0.02–0.10) microwave dielectric ceramics were fabricated by the solid-state reaction method and investigated in terms of crystal structure, chemical bond properties, and dielectric properties were analyzed. The XRD data indicates that (Mg1-xZnx)3(PO4)2 samples belong to the monoclinic crystal with P21/c space group and no detectable secondary phases. The Rietveld refinement was employed to obtain crystal parameters. In addition, the results of chemical bond properties reveal that the lattice energy and ionicity of Mg (2)–O (3) bonds play a primary effect on the dielectric loss and dielectric constant, respectively. The bond energy of Mg(l)-O (2) bonds plays a dominant role in thermal stability. The far-infrared spectroscopy was employed to explore the intrinsic dielectric parameters, and the results showed that peaks below 400 cm-l contributed 78.9 % to ε′ and 99.1 % to ε″. The Raman data demonstrated that the Raman shift and FWHM exhibit an important influence on Q × f. The optimal performance was achieved in (Mg0.94Zn0.06)3(PO4)2 ceramics: εr = 5.00, Q × f = 84,674 GHz, τf = −59.98 ppm/°C.

Improvement on properties of Sr2+ doped perovskite-type ceramic for thermal protective coating: A comprehensive evaluation

Perovskite-type aluminates hold significant promise for applications as thermal protective coatings (TPCs), but their inferior properties necessitate further optimization. In this study, PrAlO3+δ (PA) and Sr2+ doped Pr1-xSrxAlO3+δ (PSA, x = 1, 2, 5 mol%) were fabricated using the solid-state reaction method. The effects of Sr2+ substitution on properties were thoroughly investigated. The results demonstrated pronounced effects of Sr2+ substitution. PSA exhibited significant lattice volume expansion and enhanced sintering resistance with increasing doping concentration. Also, doping strategy effectively decreased thermal conductivity of PSA 4.38 W/(m·K) at room temperature to 3.48 W/(m·K) at 900 °C, decreasing by about 15 % in comparison to that of PA (6.21–4.07 W/(m·K)). Moreover, mechanical properties of PSA were improved, presenting the lowest elastic modulus (118.7 GPa) in contrast to that of PA (344.3 GPa). Most importantly, despite the lattice distortion caused by doping leading to limited improvement in infrared emissivity in the range of 8–14 μm, the infrared emissivity of PSA was significantly enhanced in the range of 3–5 μm. A highest average emissivity of 0.875 was achieved with x = 2 mol%, representing a 10 % enhancement compared to that of PA (0.796). Furthermore, the enhancement mechanisms were systematically elucidated.

Relationship between structure and microwave dielectric properties of new low-K garnet-type Ca3Cr2Ge3O12 ceramics

In order to solve the problem of signal delay, a novel low-K Ca3Cr2Ge3O12 ceramic for 5G and millimeter-wave communication was prepared by a solid-state reaction method. XRD and Rietveld refinement results confirm that it belongs to the garnet structure with the Ia-3d space group. The shrinkage rate of the sample sintered at 1350 °C reached 11.9 %, and the relative density exceeded 94.3 %. Excellent microwave dielectric properties were obtained. The permittivity was 8.38, the quality factor was 23,107 GHz, and the temperature coefficient of resonant frequency was −43.57 ppm/°C. The relationship between the crystal structure and microwave dielectric properties of ceramics was further studied. The results show that lattice vibration, stacking fraction and bond strength have a great influence on the Q × f value of ceramics, and the bond valence parameter is the key factor affecting the temperature stability. In addition, the theoretical quality factor of the ceramic can reach ∼13,0000 GHz by far-infrared reflection spectroscopy, and the ceramic has great research potential. The development of Ca3Cr2Ge3O12 ceramics and the study of microwave dielectric properties have filled the research gap of related systems. The excellent microwave dielectric properties indicate that it can be used as an alternative material for the preparation of components in the field of communication.

Study of magnetocaloric properties of small Bi-doped Pr0.55Ca0.05Ba0.40Mn1−xBixO3 manganites

Here, we investigated the magnetic and magnetocaloric (MC) properties of manganites labeled PrCaBaMnO and PrCaBaMnBiO, with compositions Pr0.55Ca0.05Ba0.40Mn1−xBixO3 (x = 0 and 0.02), respectively. The solid-state reaction method was used for sample preparation, and the structural properties were checked using X-ray diffraction (XRD). Temperature dependence of magnetization (M(T)) measurements was carried out in the range of 5–300 K under 100 Oe field to determine the transition temperature of the manganites. Magnetic entropy change (-ΔSM\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-\\Delta {S}_{\ ext{M}}$$\\end{document}) values were computed from field-dependent magnetization (M(H)) measurements. For the 2 T magnetic field values, the -ΔSMmax\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-\\Delta {{S}_{ }}_{\ ext{M}}^{\ ext{max}}$$\\end{document} values for the PrCaBaMnO and PrCaBaMnBiO manganites are 3.15 and 2.86 Jkg-1K-1, respectively. Relative Cooling Power (RCP) values were calculated from the temperature dependence of -ΔSM\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-\\Delta {S}_{\ ext{M}}$$\\end{document} (T) curves, resulting in 82.4 and 88.6 Jkg-1 for PrCaBaMnO and PrCaBaMnBiO, respectively. Banerjee’s criterion and Franco’s universal master curve confirmed that the transition type for the studied manganites is second order.

Tuning the structural, optical, and dielectric properties of europium-doped barium titanate ceramics

This study explores the optical and dielectric properties of pure and europium-doped barium titanate ceramics with formula Ba1−3x/2EuxTiO3 (x=0,0.005,0.015and0.025\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$x=0,0.005, 0.015\ ext{ and }0.025$$\\end{document}). The materials were synthesized using the solid-state reaction method. The influence of Eu + 3 ion incorporation on the crystal structure was examined using XRD, which indicated the formation of a cubic phase. Lattice parameter measurements showed excellent agreement with various theoretical models for predicting the lattice constant, with an average error of only 0.20%. UV–visible spectroscopy analysis is utilized to investigate optical characteristics, revealing a decrease in the optical band gap from 2.65 to 2.77 eV post-Eu doping, which is notably lower than the bulk barium titanate value of 3.2 eV. Materials with smaller band gaps are more suited for optoelectronic applications like photodetectors and light-emitting diodes (LEDs). The dielectric response of europium-doped barium titanate was studied across a frequency range of 1 kHz to 2 MHz and a temperature range of 77 to 300 K, showing remarkable stability. The frequency-dependent dielectric analysis revealed that the dielectric constant initially increased with increasing doping concentration, but decreased at higher concentrations. These results suggest that europium-doped barium titanate holds significant promise for future electronic device applications due to its enhanced optical and dielectric properties.

Role of Bi/Te co-dopants on the thermoelectric properties of SnSe polycrystals: an experimental and theoretical investigation

A sustainable solution to the energy crisis may be found in thermoelectric materials and generators, capable of transforming thermal energy into electrical energy or vice versa. SnSe is one of the emerging thermoelectric materials with distinctive properties. The main advantages of this compound are earth-abundant, inexpensive, non-toxic and it is also known for its high thermoelectric performance. Here we prepared Bi/Te co-doped SnSe polycrystals; whereas, Bi and Te are added with different compositions such as (x = 0.0,0.02,0.04,0.06 and y = 0.03) in (Sn1-xBixSe1-YTeY) matrix by using the solid-state reaction method. XRD data confirms the samples belong to the orthorhombic crystal system with the Pnma space group. DFT calculations were used to see structural stability and electronic properties for pure and doped SnSe samples. Temperature-dependent semiconducting behavior of the samples has been demonstrated by electrical resistivity. The Seebeck coefficient, correlated with carrier concentration and mobility, validates the p-type behavior for the pristine samples and the n-type behavior for co-doped samples. The dominant behavior of phonon scattering has been demonstrated by thermal conductivity analysis. After co-doping there is decrement in total thermal conductivity was observed which 1.3 times lower than SnSe. A theoretical calculation was used to validate experimental results to estimate electrical properties, Seebeck coefficient, specific heat capacity, thermal conductivity, and power factor using Quantum espresso code with Boltzmann transport Equation. 4% Bi-doped sample displayed a significant increment in electrical conductivity and an enhanced Seebeck coefficient, which led to the power factor enhancement of approximately 2.0 times in contrast to the pristine sample and enhanced ZT of about 0.055 which is 3.43 times higher than the pristine SnSe.Graphical abstract

Enhanced energy storage properties promoted by the synergistic effects of aging effects and relaxor behavior in Ce–Mn co-doped Sr0.4Ba0.6Nb2O6 ferroelectric ceramics

In this work, Ce–Mn co-doped Sr0.4Ba0.6Nb2O6 ferroelectric ceramics were prepared by the conventional solid state reaction method. Aging effects induced by acceptor doping and relaxor behavior induced by donor doping were achieved simultaneously in Sr0.4-3x/2Ba0.6Cex(Nb0.96Mn0.04)2O6 (SBN40–4Mn-xCe) ceramics. The results show that the doping of Ce ions enters into the lattice of SBN and substitute the Sr ions, which give rise to the cell volume decreasing. The diffuseness fitting results suggest that all the co-doped samples own the relaxor characteristic. The polarization electric (P-E) loops of aged SBN40–4Mn-xCe ceramics presents constricted tendency and slimmer shape at the mean time. As a result, the Pmax-Pr values of the aged samples are higher than that of unaged samples and get an enhanced energy storage performance, which are benefited from the synergistic effects of aging effects and relaxor behavior. The composition of x = 0.04 obtained the maximum Wrec with 0.90 J/cm3 and η with 89 % after aging. Therefore, the current work may provide some guidance for improving the energy storage performance from the perspective of changing the shape of P-E loop by inducing aging behavior and relaxor behavior simultaneously.

Sintering behavior, microstructure and dielectric properties of a novel low loss SrEr2O4 microwave ceramic

In this paper, a novel SrEr2O4 ceramic with relative densities exceeding 96% was synthesized by a conventional solid-state reaction method. Furthermore, investigations of the correlations between its crystal structure, microstructure, and microwave dielectric properties were carried out. Rietveld refinements show that the SrEr2O4 ceramics crystallize in the orthorhombic with the space group Pnam. The SrEr2O4 ceramic sintered at 1575 °C exhibits the good performance of permittivity (εr) = 14.44, quality factor (Q×f) = 23271 GHz, and resonant temperature frequency coefficient (τf) = –21.5 ppm/°C, which is attributed to its high lattice energy, packing fraction, and relative density. In addition, to satisfy the requirement of temperature stability for communication devices, near-zero τf value is obtained by adding CaTiO3 at the cost of a small quality factor loss. The SrEr2O4 + 1.25 wt% CaTiO3 composite exhibits decent properties with εr = 18.57, Q×f = 19940 GHz, and τf = +3.99 ppm/°C, making it an ideal candidate for microwave band applications.

Concentration-dependent luminescence characterization of terbium-doped strontium aluminate nanophosphors.

The present investigation describes the synthesis of luminescent terbium-doped strontium aluminate nanoparticles emitting bright green light, which were synthesized through a solid-state reaction method assisted by microwave radiation. Various samples containing different concentrations of Tb were synthesized, and an analysis of their structural and morphological features was conducted using powder x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The band gaps of the samples were determined utilizing the Kubelka-Munk method. The quenching mechanism observed was identified to be due to dipole-dipole interaction using the Dexter theory. The optimized sample with a terbium concentration of 4at.% has a luminescence lifetime of 1.05 ms with 20.62% quantum efficiency. The results of this study indicate that the terbium-doped strontium aluminate fluorescent nanoparticles exhibit promising potential for a wide range of applications, including bioimaging, sensing and solid-state lighting.

Investigation of BSCCO Superconductors with Ga Substitution by Solid State Method

Samples of (Bi2-xGax)Sr2CaCu2O2 superconductors with varying Ga substitution levels (x=0, 0.06, 0.12, 0.20) were synthesized using the solid-state reaction method. The effects of partial substitution of bismuth and gallium elements on the BSCCO structure were investigated in terms of their electrical, magnetic, structural, and mechanical properties. X-ray diffraction (XRD) was used to determine the crystalline phases, and samples A and B exhibited sharp peaks, indicating well-crystallized material with no Ga2O3 phase. SEM images were used to obtain microscopic views of all samples, and the elemental compositions of each element were determined from EDX spectra. The critical temperature was calculated from R-t measurements, and Sample A exhibited the highest Tc at 96K. Magnetic properties were investigated for all samples, including magnetic hysteresis behavior and magnetic moment. The critical current density (Jc) values were calculated using the Bean model by utilizing magnetic hysteresis.

Influence of NiCo2O4/PbS nanocomposite on the structural, optical and electrical properties of Polymethyl Methacrylate polymer

Poly(methyl methacrylate) (PMMA)/(1-x)NiCo2O4/xPbS polymers were prepared using the casting hydrothermal and solid state reaction methods. The different phases formed in (1-x)NiCo2O4/xPbS nanocomposites were determined using the X-ray diffraction (XRD) technique. XRD and scanning electron microscopy (SEM) techniques were used to explore the structure and morphology of the formed polymers. The influence of (1-x)NiCo2O4/xPbS nanocomposite doping on the absorption, transmission, extinction coefficient, absorption coefficient, refractive index, nonlinear optical parameters and fluorescence spectra of PMMA polymer was explored using diffused reflectance and fluorescence spectrophotometer techniques. The direct and indirect optical band gap (Eg) values decreased from (5.31 and 5.06) eV (for undoped PMMA) to (4.66 and 4.17) eV (for doped PMMA with x = 0.1 filler), respectively. Several models based on the Eg value were used to find out the value of the refractive index of different polymers. The impact of doping on the dielectric constant, relaxation time, energy density, electrical conductivity and electric modulus of the PMMA polymer was also studied using an LCR meter.

Impedance spectroscopy and electrical conductivity of 0.7Bi(1−x)NdxFeO3–0.3BaTiO3 ferroelectric ceramics

0.7Bi[Formula: see text]NdxFeO3–0.3BaTiO3 (BNFO–BTO, [Formula: see text], 0.010, 0.020 and 0.050) ceramics were fabricated using the high-temperature solid-state reaction method. The X-ray diffraction (XRD) patterns revealed that the primary phase in these ceramics was pseudocubic. The Scanning Electron Microscopy (SEM) micrographs exhibited dense microstructures throughout all BNFO–BTO ceramics. Furthermore, the temperature dependence of dielectric behaviors and ferroelectric hysteresis loop shapes suggested the occurrence of a relaxor ferroelectric-type phase transition in BNFO–BTO ceramics. Additionally, the frequency dispersion characteristics and remnant polarization were enhanced with increasing substitution of Bi[Formula: see text] by Nd[Formula: see text]. Conducted impedance analysis on 0.7Bi[Formula: see text]NdxFeO3–0.3BaTiO3 ceramics and two dielectric responses of the grain at high frequency and grain boundary at low frequency were illustrated, respectively. The combination of imaginary impedance ([Formula: see text] and imaginary modulus ([Formula: see text] versus log[Formula: see text]f plots revealed that the charge carriers’ motion was not entirely long-range, short-range migration also exists. Through calculations based on Curie–Weiss Law, the relaxation activation energy ([Formula: see text] and conductance activation energy ([Formula: see text] were investigated, confirming that doping Nd[Formula: see text] effectively mitigates the concentration of oxygen vacancies (OVs) and prevents the formation of oxygen vacancies clusters, ultimately suppressing conductivity in BNFO–BTO ceramics.