Journal of Materials Science: Materials in Electronics最新文献

Herein, we demonstrated that controlled bath temperature can significantly enhance the structural, magnetic, and anti-corrosive characteristics of NiFeCoAlP thin films. XRD profiles confirmed the formation of a solid solution phase with mixed FCC and BCC structures with crystallite sizes ranging from 17 to 24 nm. Higher temperatures resulted in grain refinement and increased dislocation density, improving film integrity. SEM revealed smoother and more homogeneous surfaces at high temperatures. The film deposited at 60 °C showed optimal magnetic behavior, achieving a high saturation magnetization of 120.18 emu/cm³ and low coercivity of 7.34 Oe in the in-plane direction, suitable for soft magnetic applications. Electrochemical analyzes showed enhanced corrosion resistance at 70 °C, with a high charge transfer resistance (R_ct = 926.4 Ω cm²), low corrosion current density (I_corr = 1.8 µA/cm²), and reduced corrosion rate (0.059 mm/y), attributed to the formation of a stable passive layer.

Energy storage technologies including batteries, supercapacitors and fuel cells are essential to cater the energy storage needs of modern electronics, electric vehicles, and renewable energy systems. Among emerging materials, MXene offer great potential in reforming the electrode design due to high capacitance, energy and power densities and conductivity. The electrochemical performance of MXene electrodes has been increasingly affected by their surface chemistry and morphology. Various types of MXene and their derivatives such as Ti₃C₂Tx and V₂CT_x have been examined with different battery and supercapacitor materials like lithium, sodium and zinc, demonstrating promising electrochemical properties and performance enhancements. Moreover, functionalized MXenes have shown enhanced electrochemical stability and cyclic stability in metal-ion batteries, and pseudocapacitive behavior in supercapacitors. The compatibility of distinctive materials with MXene to form composite electrode and their synthesis method also have high influence on their performance in energy storage system. Therefore, several approaches have been developed in the recent times, such as hybridization, elemental doping, and controlled interlayer spacing that can be explored and advanced further. These strategies provide a substantial solution to restacking of MXene nanosheets, modest ion transportation and energy storing capacity. This review explores the advancements, emphasizing the evolving role of MXene in next-generation storage technologies.

In this work, TiN–Al₂O₃ composites were synthesized via a wet-chemical method and investigated as electrode materials for supercapacitor applications. Among the prepared samples, the TiN 40%–Al₂O₃ (ZR-2) composite exhibited superior crystallinity, making it a promising electrode material. The ZR-2 electrode delivered a high specific capacitance of 848 F g⁻¹, along with an energy density (E_d) of 22.88 Wh kg⁻¹ and a power density (P_d) of 800 W kg⁻¹ at 1 A g⁻¹. Moreover, it maintained 96.4% capacitance retention after 10000 charge–discharge cycles, demonstrating excellent stability and durability. These results highlight the potential of TiN–Al₂O₃ composites, particularly ZR-2, as efficient electrode materials for advanced energy storage devices.

A series of novel broadband blue-emitting Ca₈(Al₁₂O₂₄)(WO₄)₂: x% Eu²⁺ (0.1≤x≤2.5) phosphors were synthesized via the solid-state method. The analysis of crystal structure and the X-ray diffraction confirms that the Ca₈(Al₁₂O₂₄)(WO₄)₂: Eu²⁺ phosphors are phase-pure and crystallize in the orthorhombic system with space group Aba2. The wide bandgap energy of the Ca₈(Al₁₂O₂₄)(WO₄)₂ host provides a suitable bandgap environment for Eu²⁺ ions. Under 325 nm excitation, the Ca₈(Al₁₂O₂₄)(WO₄)₂: Eu²⁺ exhibits a broad blue-emitting band in the range of 380–550 nm, resulting from the 4f⁶5d¹→4f⁷ transition of Eu²⁺. As the concentration of Eu²⁺ increases, the emission peak of Ca₈(Al₁₂O₂₄)(WO₄)₂: Eu²⁺ undergoes a redshift, originating from the site competition by Eu²⁺ doping. Concurrently, due to concentration quenching, the emission intensity initially increases and subsequent decreases, reaching a maximum at an optimal Eu²⁺ doping concentration of 0.3%. The concentration quenching mechanism was confirmed to be electric dipole-dipole interaction. Additionally, the optimally doped Ca₈(Al₁₂O₂₄)(WO₄)₂: 0.3% Eu²⁺ phosphor exhibits bright blue emission with CIE coordinates of (0.150, 0.054) and high color purity of 92.0%. These results demonstrate that this novel type of blue broadband Ca₈(Al₁₂O₂₄)(WO₄)₂: Eu²⁺ phosphor has great potential in the field of optical applications under excitation of near-ultraviolet light.

Sb_xSe_y thin films were obtained by chemical-molecular beam deposition (CMBD) on soda–limeglass from high-purity Sb and Se precursors at 450 °C substrate temperature. By the exact control of separate sources temperature, Sb_xSe_y thin films with stoichiometric and different compositions were successfully obtained. The Sb_xSe_y thin films were characterized in terms of their elemental and phase composition, along with their crystal structure, using techniques such as energy-dispersive X-ray microanalysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The bandgap of the films, ranging between 1.07 and 1.26 eV, was determined by analyzing absorption spectra derived from transmittance and reflectance measurements using a spectrophotometer. The electrical properties of samples were measured by the two-probe method. The samples showed p-type conductivity at Sb/Se ≤ 0.77 and n-type conductivity at Sb/Se ≥ 0.95. From this behavior, we infer the presence of a “turning point” at Sb/Se = 0.77, which corresponds to the p-type conductivity of Sb₂Se₃ thin films.

Nickel oxide (NiO) thin films with varying thicknesses (5–100 nm) were deposited on fused silica at room temperature via RF magnetron sputtering in pure argon. Optimal deposition conditions were established by analyzing deposition rates under varying pressures (5–25 mTorr) and powers (75–250 W). Structural, optical, and electrical properties were studied using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–VIS spectroscopy, and I–V measurements. XRD confirmed a face-centered cubic structure, with a preferred orientation shift from (111) to (200) as thickness increased, and the appearance of the (220) peak beyond 20 nm. Crystallite size, microstrain, and dislocation density stabilized for films thicker than 20 nm. EDS analysis revealed uniform growth and an increasing Ni:O ratio with thickness, affecting transmittance and resistivity. A slight bandgap increase (3.52 to 3.54 eV) and a significant resistivity drop (to 3.0 × 10^–3 Ω m) were observed with increasing thickness, attributed to reduced oxygen concentration and improved film quality.

The scope of our research encompasses is the preparation of a liquid crystalline compound with a low molecular weight through the process of direct alkylation of para-pentyloxy benzaldehyde. The effect of the bromo terminal group on the optical properties of pure nematic liquid crystals (LCs) was investigated and studied the effect of changes in the molecular shape on some physical parameters, such as optical transmittance and activation energy as well as dielectric anisotropy. Based on the results of optical transmittance measurements as a function of temperature and bias voltage, the LC seems to possess an anisotropic character. FTIR spectrophotometer was conducted to investigate the molecular structure and differential Scanning Calorimeter (DSC) was used to characterize the mesomorphic characteristics of the molecules as well as the polarizing microscopy (POM) used to show the optical texture of the samples as they transition from the isotropic phase to the nematic phase. Two helium–neon lasers with different wavelengths (λ = 612 nm and 543.5 nm) were chosen to study the holographic properties of azo-dye methyl red (MR)/Schiff base LC-doped Poly(methyl methacrylate) (PMMA) film. The diffraction efficiency was 5.812% for the first order. The nonlinear refractive index (NRX) for randomly orientated azo-dye MR/Schiff base LC-doped PMMA films was measured by counting the number of rings seen by a diffraction technique and is found to be the order of (0.5–4.51) × 10⁻⁵ cm²/W for (0.3–0.55) doping ratios respectively. We have replicated the diffraction patterns using a well-known theoretical model based on wave theory. The results have been shown the reasonable agreement between the theoretical model and the experimental results.

MXene has emerged as a promising candidate for electromagnetic wave absorbing (EMA) materials. However, its performance in the high-frequency range remains suboptimal. To enhance its overall EMA capabilities across a broader frequency spectrum, this study systematically tuned the molar ratio of Ti₃C₂T_x/TiO₂/CdS composites synthesized by a hydrothermal method. We optimized the interfacial charge transfer and accumulation to utilize the synergistic effect of dielectric loss and conduction loss to improve EMA performance. Experimental results exhibited that Ti₃C₂T_x/TiO₂/CdS-1 (CdS:Ti₃C₂T_x = 0.2:1) composite had excellent performance: a minimum reflection loss (RL_min) of -52.02 dB at 14.16 GHz, a matching thickness of only 1.45 mm and an effective absorption bandwidth (EAB) of 4.24 GHz. By adjusting the CdS content, the study optimized interfacial charge transfer and reduced excessive conductivity of pure MXene, which typically caused strong electromagnetic reflection. CdS acted as a "conductivity buffer", and electron transferred from Ti₃C₂T_x to CdS, decreasing interface transfer resistance and improving conduction loss. Therefore, MXene provided a high-conductivity 2D framework, TiO₂ introduced local defects and polarizable groups, and CdS modulated conductivity and enhanced interfacial charge transfer, achieving a balanced loss mechanism. This paper provides a reference method for improving EMA performance of MXene-based composites.

This study presents a comparative investigation of undoped and potassium-doped zinc oxide (K:ZnO) nanoparticles with varying particle sizes, synthesized via a sol–gel method and sintered at 500 °C for 3 and 5 h. The structural properties were characterized using X-ray diffraction (XRD), which confirmed the formation of single-phase hexagonal wurtzite structures. Crystallite size analysis via the Debye–Scherrer equation revealed a decrease in size (43.6 and 51.7 nm), reduced to 37.6 and 36.0 nm for (ZnO–3 h), (ZnO–5 h), (K:ZnO–3 h), and (K:ZnO–5 h), respectively, upon K⁺ incorporation. Scanning electron microscopy (SEM) confirmed quasi-spherical grains with average particle sizes of − 48 nm (ZnO–3 h), − 63 nm (ZnO–5 h), − 52 nm (K:ZnO–3 h), and − 70 nm (K:ZnO–5 h), and energy-dispersive X-ray spectroscopy (EDX) validated the morphological uniformity and successful K⁺ doping. Dielectric spectroscopy showed enhanced dielectric constant (ε′) with temperature and longer sintering. AC conductivity increased with K-doping, especially at low frequencies and high temperatures, due to increased charge carrier density and interfacial polarization. Conversely, dielectric loss and impedance were reduced, reflecting improved electrical stability. Impedance spectroscopy and complex modulus analysis revealed thermally activated non-Debye relaxation behavior, with shorter relaxation times in doped and long-sintered samples. By combining controlled K⁺ incorporation with optimized sintering time, we demonstrate a simple processing route to tune crystallite size, defect chemistry, and non-Debye dielectric relaxation in ZnO nanoparticles. The joint structural and impedance analysis shows that K⁺ doping together with longer sintering strongly reduces grain boundary resistance while suppressing crystallite growth, providing a synergistic strategy to engineer ZnO-based dielectrics for low-loss and varistor-type electronic applications.