Journal of Materials Science: Materials in Electronics最新文献

Wearable self-healable strain sensors are gaining significant attention for applications in healthcare, robotics, and human–computer interaction. However, existing sensors face key challenges, including limited healing efficiency, low sensitivity to mechanical strain, and inadequate durability under repeated stress. Addressing these limitations, this study presents a novel strain sensor combining a polyurethane (PU) substrate with magnetic iron oxide nanoparticles (MIONPs) and silver flakes to enhance self-healing capabilities and strain sensitivity. The integration of MIONPs enables a self-healing efficiency of 96.6% within 24 h, a notable improvement over previous technologies that often require longer recovery times and achieve lower healing rates. Additionally, the sensor achieves a high gauge factor of 271.4 at 35% strain, representing a fourfold increase in sensitivity compared to traditional strain sensors. The sensor's responsiveness to external magnetic fields, with a magnetic sensitivity of 0.0049 T⁻¹, further expands its application potential in areas like magnetically controlled devices and soft robotics. This work significantly advances multifunctional, self-healing strain sensors by addressing current limitations and offering improved performance for long-term, sustainable applications.

The transceiver module serves as the core components of active phased array radar systems. During reflow soldering using Sn-3.0Ag-0.5Cu solder, the frequent failure of solder joints significantly restricts the yield rate of the transceiver module production. The solder joint is between the housing module and the AuPtPd pad predeposited on the low-temperature co-fired ceramic substrate. This study aims to investigate the influences of the reflow soldering process on the microstructure and shear strength of the solder joints. Solder joints were prepared under soldering temperatures ranging from 230 °C to 270 °C and soldering times ranging from 0 to 240 s. Research findings indicate that at temperatures below 250 °C or soldering time less than 120 s, a thin layer of Au–Sn intermetallic compounds (IMC) film can be formed in the solder joint with minimal consumption of the AuPtPd pad. With increasing temperature or soldering time, shear strength exhibits gradual increases and minimal variability. Conversely, when the temperature exceeds 250 °C or the soldering time surpasses 120 s, more IMC is formed with the greater consumption of the AuPtPd pad, resulting in the formation of a thicker, discontinuous, and uneven IMC layer, leading to a rapid decrease in the shear strength of the solder joint. Considering the overall joint strength, soldering at 250 °C for 120 s is identified as the optimal process, achieving a shear strength of 61.48 MPa.

This paper is focused on thermoluminescence study of Mn⁴⁺-doped zinc aluminate nanophosphor with different Mn concentrations (0.5–3 mol %). The samples were chemically synthesized via microwave combustion method and annealed at 900 °C temperature. Nanoregime, single-phase spinel structure formation was confirmed by XRD and further analysed by Rietveld refinement method. The photoluminescence (PL) spectrum and PL decay curve revealed 745 nm emission under ultraviolet excitation wavelength, and afterglow decay time of the order of milliseconds. The thermoluminescence (TL) response was carried out using UV irradiation (254 nm) with different exposure time intervals. The effect of Mn concentration (0.5–3 mol %) and UV exposure time on TL glow curve of zinc aluminate was presented and discussed. A broad TL peak with 40 min UV irradiation exposure time was observed. Progression in TL intensity was observed with Mn concentration from 0.5 to 2% and above 2 mol %, and TL intensity was quenched. Also, a noticeable TL peak shifting was found for higher Mn⁴⁺ ions concentration. The optimum TL peak corresponding to 40 min exposure time (for 2 mol % Mn) was deconvoluted into two peaks at 395 K and 422 K temperature. The prepared ZnAl₂O₄:Mn⁴⁺ (2 mol %) nanophosphor showed linear dose response, essential property of dosimeters. The assessment of trap creation and trap depth was analysed by calculating the trap parameters. Two different methods, computerized glow curve deconvolution (CGCD) and Chen’s peak shape (CPS) method, were applied to calculate various kinetic TL parameters, e.g. order of kinetics (b), trap depth (activation energy E_av), and frequency factor (S). The measured trap depth suggested the involvement of shallow trap states for recombination process. This study will be immensely helpful in understanding the thermoluminescence behaviour of Mn⁴⁺-doped zinc aluminate nanophosphor for UV-TLD applications.

The metal–organic framework (MOF) derivatives are considered novel microwave absorption material (MAM) with significant potential for applications. However, the challenge persists in achieving MOF-derived MAM with lower filling ratio and wider effective absorption bands. Constructing a uniform carbon nanotube (CNT) interconnected networks to enhance dielectric loss is considered an effective strategy to solve these problems, yet the challenge lies in its construction using a straightforward approach. Herein, we investigated the unique features of MOF as precursors for fabrication of one-dimensional (1D) micro-nano mixed scale hierarchical porous carbon architecture for highly efficient MAM. A uniform CNT interconnected networks on the surface of 1D rod-like MOF derivatives was constructed via a simple self-polymerization and in-situ pyrolysis. The effects of the Co/Zn molar ratio and pyrolysis temperature on the microstructure and microwave absorption performance of the composites were investigated. By controlling the CNT growth and magnetic components content, the composites exhibited outstanding microwave absorption performance and achieved a minimum reflection loss of −55.3 dB at 1.71 mm and maximum effective bandwidth of 5.5 GHz at a thin thickness of 1.82 mm. This work presents a novel approach for the utilization of MOF in fabricating magnetic carbon-based MAM with wide absorption bands and low filler ratios.

In the present study, lead-free Sn–Cu–Al–Mg-based solder alloys for electronics packaging were produced. Effects of thermal shock and thermal stress on the crack formation in the Sn-based solder alloys were investigated. Lead-free quaternary Sn–Cu–Al–Mg-based solder alloys were produced by using mechanical alloying and powder metallurgy route. Soldering involves using a molten filler metal to wet the surfaces of a joint. Wave soldering is a method for mass assembly of printed circuit boards involving through holes, surface. Lead-free solder alloys must show high wettability, suitable mechanical properties, electrical conductivity, high electrochemical corrosion resistance, and low cost. Mechanical alloying and powder metallurgy method were used in order to prevent formation of intermetallics and formation of voids. Mechanical alloying–powder metallurgy method could reduce the micro/macro-segregation and provide homogeneous microstructure. Initially, elemental metal powders were mechanically alloyed in a ball mill by using zirconia balls in order to produce alloy powders. Then, the alloy powders were compacted at 300 MPa and then the green specimens were sintered at 180 °C for 60 min. Nondestructive ultrasonic tests and eddy current tests were used for characterization of the solder alloy specimens. Elastic modulus of the Sn alloys was determined by ultrasonic measurements. Electrical conductivity of the specimens was determined by using eddy current tests. Microstructure was studied by scanning electron microscope. Effects of thermal shock and thermal stress on the crack formation in the alloys were investigated by heat treatment cycles in a chamber furnace. Heating cycles for thermal stress consist of heating to 150 °C and slow cooling. Heating cycles for the thermal shock consist of heating and quenching. In addition, electrochemical corrosion behaviour of the Sn solder alloys was investigated in NaCl solution.

The advancement of hetero-structured ReRAM devices has received increasing attention in the field of optoelectronic applications. In the past few years, zinc oxide (ZnO), an II–VI group semiconductor, has garnered significant interest for ReRAM applications. The present study focuses on the fabrication of bilayers (p–n junction-based ReRAM devices) using n-type ZnO and p-type PEDOT:PSS layer. Using the spray pyrolysis technique, ZnO thin-film layers were formed onto glass substrate. The PEDOT:PSS layers were formed by the spin coating method. The prepared PEDOT:PSS and ZnO bilayers were analyzed by XRD, FESEM, and Raman spectroscopic analysis. The structural analysis of ZnO thin-film layers confirms the presence of the wurtzite phase, highlighting their crystalline nature. Cross-sectional morphological studies demonstrate that all layers are uniformly and distinctly formed, ensuring high-quality formation. The PEDOT:PSS and ZnO thin-film layers were formed onto the ITO substrate, which was sandwiched between the bottom ITO and top (Ag) electrodes. The current–voltage (I–V) characteristics and double logarithmic I–V plots of the fabricated PEDOT:PSS/ZnO heterojunction devices were analyzed for their suitability in ReRAM applications. The results indicate that the devices exhibit bipolar resistive switching behavior, with the conduction mechanism primarily governed by the formation and rupture of conductive filaments (CFs) within the switching layers.

This paper presents the pioneering creation and use of a nanosensor to detect harmful food dyes, including Sunset Yellow (SY). This sensitive platform was created by adding Tin dioxide-Manganese dioxide nanocomposite onto the surface of a graphite electrode (GE). The sensing capabilities of the proposed nanosensor with Tin dioxide-Manganese dioxide (SnO₂–MnO₂) drop cast on GE were demonstrated through the use of electrochemical measurements, such as differential pulse voltammetry, Chronoamperometry, linear sweep voltammetry, square wave voltammetry, and cyclic voltammetry. The investigation of several factors enabled the optimization of the ideal response conditions for the target analyte. The study demonstrated that the SnO₂–MnO₂-GE nanocomposite significantly enhanced the signals of the chosen food dye in comparison to the unmodified GE. This improvement can be attributed to the combined effect of Tin dioxide and Manganese dioxide nanocomposite, which work together synergistically. The SnO₂–MnO₂-GE system can detect Sunset Yellow with a limit of detection of 0.89 µM under ideal conditions. Moreover, the exceptional stability, limit of detection and sensitivity of the suggested electrochemical platform shows its potential applicability in the real-world sample analysis.

This research reveals the results of a comprehensive analysis of the optical and structural features of zinc selenide (ZnSe) thin film. The studied film was synthesized using the thermal evaporation method after preparation on the glass substrate. The film’s structural characteristics, which have been determined by using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD), confirm the polycrystalline nature of the films with a predominant cubic zinc-blende structure. The surface morphology investigated through SEM reveals a uniform grain distribution with minimal surface defects, indicating high-quality film formation. In order to examine the optical characteristics, the ultraviolet–visible spectroscopy method is used in a spectral range between 300 and 900 nm. In this way, the ultraviolet–visible spectroscopy data are utilized to obtain optical features such as extinction coefficient (k), optical band gap (E_g), refractive index (n), absorption coefficient (α), and optical conductivity (σ_opt). These optical properties are assessed using ultraviolet–visible spectroscopy, revealing a direct band gap of approximately 2.88 eV, which is consistent with the bulk properties of ZnSe and suitable for optoelectronic applications. The results of this study clearly show that the studied ZnSe film can be used for optoelectronic device applications.

Polymeric composites based on PVA doped with TiO₂, WO₃, and Co₃O₄ are the subject of the study. A range of physicochemical techniques was used to examine the structure of PVA-based composites. A changing absorption edge for PVA is also seen in the optical studies; it begins at 3.8 eV and drops to 2.4 eV for the PVA-TiO₂-WO₃ combination. Furthermore, the indirect band gap for all composites doped with TiO₂, WO₃, and Co₃O₄ lowers, reaching 2.8 eV in the PVA-TiO₂-WO₃ composite. Pure PVA has the greatest value (5.7 eV). The refractive index, on the other hand, shows 1.67 in PVA and 2.08 in PVA-TiO₂-WO₃ composite. Additionally, the dielectric constant decreased from roughly 28 for PVA and PVA-TiO₂-WO₃- Co₃O₄ composite to less than 20 in PVA-TiO₂-WO₃, but increased to ~ 45 in PVA-TiO₂ composite. PVA composites exhibited distinct behavior consistent with previous research, according to optical and dielectric measurements. As a result, the studied NCs offer a potentially helpful composition for optoelectronic applications.

This research investigated the magnetic, microstructure, and thermal behavior of Co₄₉Fe₂₁Zr₁₀Nb₅B₁₅ alloyed powder prepared by ball milling method. The milled samples were characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, differential scanning calorimetry, and vibrating sample magnetometry. The results demonstrated that after 40 h of milling, an iron-based solid solution phase began to form, ultimately leading to a partially solid solution with undissolved zirconium and cobalt after 180 h. The final average crystallite size reached 23 nm with a mean particle size of about 3.4 μm. The saturation magnetization of the final sample was relatively high compared to previous reports. Coercivity values showed a continuous increase from 40 to 180 h of milling time. The thermal analysis of the alloy sample exhibited three exothermic peaks, providing insights into the phase transformations of the alloy. The findings indicated soft ferromagnetic behavior, particularly for the annealed samples.