Journal of Materials Science: Materials in Electronics最新文献

As human exposure to non-ionizing electromagnetic (EM) radiation increases, concerns regarding its long-term health effects have prompted the search for effective shielding materials. Traditional shielding materials, while effective, often come with high production costs, complex processing requirements, or environmental concerns. Therefore, materials that are affordable, flexible, biocompatible, and easy to manufacture are in high demand for various applications, ranging from consumer electronics to medical devices, where both performance and safety are crucial. This paper investigates the potential of self-prepared silver cellulose-acetate composite as a shield against non-ionizing EM radiation. The composite’s effectiveness was tested at various silver-to-cellulose ratios (20, 40, 60, and 80%) against frequencies ranging from 1 to 10 GHz, encompassing common sources of radiation exposure. The results showed that by placing the silver cellulose-acetate composite in front of the fired clay, transmission can be significantly reduced, with the 60% silver composition showing the highest effectiveness. These findings highlight the potential of silver cellulose acetate composites as highly effective materials for electromagnetic shielding, possessing a range of desirable characteristics.

In this study, (Bi_0.5Na_0.5)_1−xPr_xTiO₃ (x = 0, 0.01, 0.03, 0.05) ceramics were fabricated using the conventional solid-state method for their potential application in electromagnetic interference (EMI) shielding within the X-band frequency range (8.2–12.4 GHz). The XRD reveals that the sample was a pure perovskite phase with a rhombohedral structure with R3c symmetry and the average crystallite size showed a decreasing trend with increasing Pr concentration up to x = 0.03 (96.50 to 67.64 nm) and then increased to 94.61 nm for x = 0.05. The FESEM micrograph confirms the grain growth without any impurity and the average grain size exhibited a decreasing trend with the rare-earth (Praseodymium) substitution in the range of 1.56–0.88 µm. Among the compositions evaluated, (Bi_0.5Na_0.5)_0.97Pr_0.03TiO₃ ceramics with a thickness of 1.4 mm exhibited the highest shielding effectiveness (SE) of 23 dB and the highest value of ε′ and μ′ was found to be 3.9 at 12.4 GHz and 9.22 at 8.2 GHz within the X-band. With a microwave absorption of above 99.9% and an absorption bandwidth of 4 GHz, the composition x = 0.03 demonstrated a minimum reflection loss of − 67.3 dB. The proposed Praseodymium-doped bismuth sodium titanate (Bi_0.5Na_0.5TiO₃) ceramics are promising materials for use as radar-absorbing compounds in electromagnetic interference (EMI) attenuators. These materials are particularly suited for applications in weather monitoring, radar tracking, and air traffic management, as well as in gigahertz-frequency antennas and commercial uses like long-term magnetic storage media for information recording and archiving.

Semiconducting bismuth borate glasses in xBi₂O₃–(1 − x)B₂O₃ system where x = 0.25, 0.50, and 0.75 (in mol.), and ZnO-glass heterostructures are studied for humidity sensing. Glass samples are prepared using melt-quenching method, whereas pristine ZnO is synthesized by sol–gel process. Heterostructure samples are obtained by adding different weight fractions of pulverized bismuth borate glass to the ZnO sol. Conducting silver paint and graphite pencil are used to make electrodes on silicon wafer and flexible paper substrates, respectively. ZnO, glass, and ZnO-glass heterostructure thin films are deposited on both the substrates through drop-casting method. Structural and microstructural changes of heterostructure films are studied using X-ray powder diffraction (XRD), and scanning electron microscope (SEM). Pristine ZnO, glass and ZnO-glass heterostructure thin film samples are tested for humidity sensing at room temperature by monitoring changes in the resistance of the samples. ZnO-glass heterostructures have shown enhanced humidity sensitivity with the lowest response and recovery times (12 and 16 s, respectively), which indicates their promising nature for humidity sensing applications. Enhanced sensing properties are attributed to the unique microstructural features of ZnO nanoparticles which are grown on glass particles through a heterogeneous nucleation process and semiconducting ZnO/glass heterostructure mechanism.

This work reports the facile synthesis of

amorphous Fe_74.5 Zr_8.5 B₁₇ magnetic nanoparticles (MNPs) through a simple NaBH₄-assisted chemical reduction method. The obtained MNPs were characterized in terms of amorphous/crystal structure, morphology, magnetic properties, composition, and crystallization kinetics. The saturation magnetization value was determined as 57.83 emu/g. The crystallization peak temperatures (T_p) and activation energy were determined to be 467.18 °C and 294 kJ/mol, respectively. Additionally, the FeZrB MNPs were combined with the BaTiO₃ NPs via ball milling at low speed, using a mass ratio of 30/70%, respectively and the magnetoelectric coefficient value for FeZrB/BaTiO₃ composite measured at a 1 kHz AC magnetic field is approximately 8.9 mV/Oe/cm. The study outcomes may provide a platform of nanotechnology for the preparation of MNPs with adjustable properties, which will be promising for practical applications.

A class of carbonaceous material called “activated carbon” (AC), gained a remarkable attention in the field of renewable energy storage technology such as supercapacitor (SC) due to the enhanced performance than the other commercial carbons. In particular, activated carbon derived from biomass gained a significant potential owing to its tunable physical/chemical properties, low-cost raw material and abundance around us. Herein, sweet flag (Acorus Calamus) derived hierarchical porous carbons with different weight percentage of activating agent (Potassium Hydroxide—KOH) and heteroatoms (thiourea) such as 30, 40 and 50 wt% are prepared through a simple hydrothermal technique. This work also aims to study the synergistic effect of undoped and nitrogen/sulfur-doped porous activated carbon for supercapacitor applications. From the obtained results, the high surface area, well-developed pores and doping of nitrogen and sulfur into AC are confirmed from Brunauer–Emmett–Teller (BET) and Field Emission Scanning Electron Microscopy (FESEM) analysis. X-ray Photoelectron spectroscopy (XPS) study reveals the chemical bond that exist between different elements in the prepared activated carbon. The electrochemical characterization of all the samples exhibits electrochemical double layer behavior and among all, the undoped activated carbon derived out of 30 wt% KOH shows higher specific capacitance value of 420 F/g at 1 A/g in H₂SO₄ electrolyte in three electrodes set up. Also, the stability test reveals good capacitive retention of 94% even after 5000 charge and discharge cycles at a current density of 5 A/g and disclose the potential of sweet flag derived AC for SC applications.

A memristor with a low power consumption, non-volatility, and adaptive abilities complex has a promising prospect in neural network computing systems due to its unique nonlinearity, memory, and local activity. Here, the Au/(1-x)Bi_0.88Nd_0.12FeO₃-xCaBi₄Ti₄O₁₅ (BNFO-CBTO, x = 0.1, 0.2, 0.3, 0.4, 0.5) non-volatile memory devices with resistance-switching (RS) behaviors are fabricated by sol–gel method. The (1-x) BNFO-xCBTO samples exhibit a tunable capacitive resistive switching behavior by the CBTO phase, i.e., the higher the content of the CBTO phase, the more obvious the phenomenon of capacitive resistance-switching behavior. Moreover, the CBTO phase improves the cyclic fatigue characteristics of the (1–x)BNFO–xCBTO samples. The lowest operating current (~ 1nA-100nA) is observed in the 0.6BNFO-0.4CBTO sample. Further, the multiple resistance states, conductive mechanisms, and synaptic behaviors with conductance continuous modulation, paired-pulse facilitation (PPF) behaviors, and excitatory postsynaptic current (EPSC) are also simulated. The 0.6BNFO-0.4CBTO non-volatile memory device with tunable abnormal resistance switching, low-power synaptic bionic potential, and a series of synaptic-like behaviors can provide a new opportunity to apply the RS behavior in high-performance computing with low power consuming, brain-like neuromorphic mimicry, and next-generation information-storage devices.

Cerium oxide fibers were synthesized using an electrospinning technique with an optimum PVP to Ce (CH₃COO)₂ ratio of 1:1. Scanning electron microscope images of CeO₂ sample calcined at 600 °C revealed highly porous and uniform fibers with an average diameter of ~ 92 nm. X-ray diffraction analysis confirmed the formation of small crystallite size, single-phase polycrystalline CeO₂ fibers. Thermo-gravimetric and differential thermal analyses of PVP/Ce-acetate composite fibers indicated complete decomposition of PVP and all volatile components below 600 °C, as confirmed by FTIR analysis. UV–Visible spectroscopy revealed a wide direct band gap of ~ 3.11 eV. The cerium oxide fibers electrical microstructure confirmed via temperature-dependent impedance studies revealed a metallic behaviour in the temperature ranging from 30–170 °C C which is attributed to the existence of high concentration of Ce⁺³ cations due to oxygen vacancies. The activation energies associated with grains and grain boundaries are 0.02267 eV and 0.025 eV, respectively. Above 170 °C, CeO₂ fibers exhibit semiconductor behaviour which is attributed to the dominance of Ce⁴⁺ cations and the associated activation energies for the grains and grain boundaries are 0.1104 eV and 0.1181 eV, respectively. The analysis of the CeO₂ fibers-based humidity sensor revealed its potential application due to the effectively polarization of the carriers at low frequencies and suggested a protonic conduction model via Grotthuss mechanism.

This study describes a straightforward process for creating the two-component nanocomposite Fe₂O₃ and CoFe₂O₄ (CFO) at several pH values, including 9, 10, and 11 (referred to as CFO_pH 9, CFO_pH 10, and CFO_pH 11). The properties of the CFO materials were also analyzed and evaluated in relation to pH values using methods such as X-ray diffraction and scanning electron microscope. The results indicated that the average particle size of the CFO material decreased from approximately 46 nm to 21 nm. Conversely, the Fe₂O₃ phase ratio in the CFO materials increased when the environmental pH was adjusted from 9 to 11. Upon reaching a charge capacity of more than 1000 mAh g⁻¹ in the first cycle, the CFO nanocomposites were also shown to be appropriate for use as the anode electrodes in lithium-ion batteries (LIBs). The CFO_pH 10 electrode exhibited a noteworthy retention of its high reversible capacity of 731.7 mAh g⁻¹ even after 50 cycles of charging and discharging. This indicates that CFO_pH 10 nanocomposite has a great potential to replace graphite as the anode material in LIBs.

The effect of pH in hydrothermal synthesis on the structural properties and photodetector performance of ZnO nanorods has been successfully investigated. Calculating the molar ratio among zinc acetate dihydrate (ZAD), methenamine (ME), and sodium hydroxide (NaOH) is important to obtain pH variations. By applying ZAD:ME (1:1), ZAD:NaOH (1:1), and ZAD:ME:NaOH (1:1:1), pH variations of 5.96 (S1), 6.80 (S2), and 7.23 (S3) were obtained, respectively. Morphological images from field-emission scanning electron microscope (FESEM) show that the average diameter of ZnO nanorods is about 75.6 nm (S1), 146.4 nm (S2), dan 173.8 nm (S3). From the optical properties analysis carried out using UV–visible spectroscopy (UV–vis), the transmittance increased by increasing the pH, while the absorption showed a different pattern. The bandgap values are 2.6, 3.1, and 3.2 eV for the S1, S2, and S3 samples, respectively. Furthermore, based on current–voltage (I-V) curves, the S3 sample has the highest UV sensitivity with a very fast response time (7.1 s for rise time and 3.9 s for decay time). This study is important to realize future optoelectronic technology.

The present work provides an in-depth analysis into the intricate interplay between the film thickness and CdCl₂ treatment on the Cadmium Telluride (CdTe) films. This investigation utilized strategically designed set of samples that vary from each other in terms of film thickness and CdCl₂ treatment. The four sets of samples having device structures: i) glass/FTO/CdS/CdTe, ii) glass/FTO/CdS/CdTe/CdCl₂, iii) glass/FTO/CdS/CdTe/CdCl₂/CdTe, and iv) glass/FTO/CdS/CdTe/CdCl₂/CdTe/CdCl₂ are fabricated. Initially, the CdTe films are analyzed by X-ray diffraction (XRD), Scanning electron microscope (SEM), Atomic force microscopy (AFM), Hall Effect measurements, and UV–Vis spectroscopy. XRD analysis revealed that CdTe films exhibited polycrystalline structure with a cubic phase displaying prominent (111) peak of orientation. However, peak intensities of samples varied with respect to film thickness and CdCl₂ treatment in the CdTe films. Similarly, from the SEM and AFM results of CdTe films, it was noticed that the surface morphology and roughness differed with respect to film thickness and CdCl₂ treatment. The electrical and optical characterizations illustrated that carrier concentration as well as conductivity and bandgap of samples varied with respect to film thickness and CdCl₂ treatment of CdTe thin films. The glass/FTO/CdS/CdTe/CdCl₂/CdTe configuration showed impressive structural, morphological, topological, and electrical results as compared to other configurations and a device of nearly 8% efficiency was obtained. J–V curves of this all the configurations have been studied in detail. Therefore, these results indicate that film thickness and CdCl₂ treatment play a vital function in improving potential of CdTe solar cells.