Journal of Materials Science: Materials in Electronics最新文献

In this study, hematite/reduced graphene oxide (α-Fe₂O₃/rGO) nanocomposites with varying GO content were synthesized and their structural, optical, surface chemical and magnetic properties were investigated. Graphene oxide was thermally reduced, as confirmed by Fourier transform infrared (FTIR) spectroscopy, which showed the disappearance of absorption peaks corresponding to oxidized functional groups in the spectrum of α-Fe₂O₃/rGO nanocomposites. Additionally, the wrinkles observed in the FESEM images are attributed to the thermal reduction process, which converted graphene oxide into reduced graphene oxide. X-ray diffraction patterns indicated a homogeneous distribution of rGO sheets in nanocomposites, as evidenced by the absence of the characteristic broad stacking peak of rGO around 26 degrees. The crystallite size of hematite nanoparticles in the nanocomposite samples varied between 22 and 31 nm, with only slight deviations in the lattice parameters of hematite observed across different GO contents. Raman spectroscopy revealed a blue shift in the G-band of rGO within the nanocomposite samples. X-ray photoelectron spectroscopy showed a positive shift in the binding energy of the Fe 2p core level spectra, signifying an interaction between rGO and the iron oxide surface. The incorporation of GO enhanced the ferromagnetic properties of hematite nanoparticles in the nanocomposite. Additionally, the nanocomposite exhibited high adsorption efficiency for methylene blue, achieving 89% degradation of a 10 µM solution with a catalytic load of 0.9 g/L. Photocatalytic experiments under sunlight further confirmed effective dye decolorization by the nanocomposite samples. The synergistic interaction of hematite and rGO in the nanocomposites was also discussed in dye decolorization.

As the miniaturization of electronic devices continues to advance, increasingly stringent demands are placed on the grain refinement of BaTiO₃ (BTO) functional ceramics. In this study, a single-step high-pressure sintering process was employed to rapidly fabricate nanoscale BTO ceramics. Through precise control of temperature and pressure, the abnormal grain growth was effectively suppressed during the sintering process, successfully mitigating the cleavage damage and the dielectric loss typically associated with columnar grains. Under the optimized sintering conditions of 600 °C and 2.0 GPa for 5 min, BTO ceramics exhibited an average grain size of 168 nm, which was an increase of 77% compared to the starting powder. The dielectric constant reached 2310 and the dielectric loss was 0.06. This work provides an effective reference for the rapid fabrication and microstructural control of nanoceramics.

The accelerated energy consumption and its impacts on our lives have led to the development of various efficient and sustainable energy storage devices. The bioderived materials are viable, cost-effective, and sustainable and hence a versatile material in fabricating energy storage devices, especially for supercapacitors. Herein a porous 3D honeycomb-like carbon is derived from the biomaterial coconut rachis which was used for the fabrication of electrodes for a supercapacitor with chitosan as the binder. A high surface area of 1,630.67 m²/g and a pore size distribution ranging from 1.5 nm to 5 nm were observed, confirming the material’s suitability for energy storage applications. Electrochemical tests revealed a maximum specific capacitance of 199 F/g at a current density of 0.62 A/g, with stable cycle life retention of 94–95% after 10,000 cycles. The optimized mass loading of the electrodes demonstrated superior performance, highlighting the potential of coconut rachis-derived carbon as an environmentally friendly and cost-effective alternative for supercapacitor applications. These findings suggest that the developed material holds promise for future energy storage systems that prioritize both performance and sustainability.

Maintaining a high Curie temperature (T_C) along with a piezoelectric coefficient (d₃₃) is crucial for the effective application of actuators and sensors. In this study, (0.36-x)BiScO₃-0.64PbTiO₃-xBaTiO₃ ceramics were synthesized via the solid-state reaction method. We thoroughly investigated the influence of BaTiO₃ (BT) additions on the structural, dielectric, ferroelectric, electrostrain and piezoelectric properties of ceramics. The X-ray diffraction (XRD) patterns showed that the phase evolution from a coexistence of coexistence of rhombohedral (R) and tetragonal (T) phases to a tetragonal (T) phase as the BT content increasing from 0 to 20%. The temperature-dependent dielectric properties exhibited a diffused phase transition with increasing BT content. The piezoelectric coefficient (d₃₃) is most noticeable at 450 pC/N, with an electromechanical coupling factor (k_P) of 57% and a Cuire temperature (T_C = 399.5 °C). In addition, a large electrostrain of S_max = 0.23% and a high remanent polarization (P_r) of 54.7 μC/cm² were observed and stable at x = 0.05. These results suggest that the BS-PT-xBT (0 ≤ x ≤ 0.20) ceramics are promising candidates for high-temperature piezoelectric applications.

Polymer nanocomposites (PNCs) of poly(methylmethacrylate-co-methacrylic acid) (P(MMA-co-MA)) / Nickel Oxide (NiO) and P(MMA-co-MA)/Cupric Oxide (CuO) (with 0.2, 0.4, 0.6, 0.8 and 1 wt% of nanofillers) have been prepared to explore the microstructural-dependent nonlinear optical (NLO) properties. The microstructure of PNCs are characterized using Positron Annihilation Lifetime Spectroscopy (PALS), Scanning Electron Microscopy (SEM), powder X-ray Diffraction (XRD), UV–Visible spectroscopy and Z-scan techniques to investigate their structural, optical and nonlinear properties. A noticeable decrease in the optical energy band gap at 0.4 wt% of NiO nanofiller and 1.0 wt% of CuO nanofiller loading, attributed to reduced crystallinity, which is confirmed by XRD results. PALS measurements reveales the presence of bigger free volume holes, which facilitate dipole polarization and significantly boost NLO performance. The findings demonstrate that P(MMA-co-MA)/NiO and P(MMA-co-MA)/CuO PNCs exhibit tunable NLO characteristics.

A new method of synthesis for NaYF₄ is reported. The method involves highly exothermic solid-state metathesis reaction between metal chlorides and NaF. The synthesis is very fast and the metathesis reaction is over within several minutes. Initiation of the reaction is marked by the appearance of the flame and the completion by its extinguishing. The product was characterised by various techniques like X-ray diffraction, electron microscopy, energy dispersive spectroscopy and elemental mapping. Mixed α and β phases were formed with cubic and hexagonal structures, respectively. Ce³⁺- and Gd³⁺-activated NaYF₄ phosphors were successfully synthesised by this method as could be judged from the typical emission and excitation spectra. Solid-state metathesis thus provides a tool for fast, simple synthesis of this important class of phosphors.

A sensitive and affordable sensor was designed for the detection of Alloxan (AXN) in food samples. Facile voltammetric techniques like linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), and cyclic voltammetry (CV) were employed to study various parameters that influence the efficiency of the fabricated sensor. The exterior structural morphology of bare graphite paste sensor (BGPS) and the electrochemically functionalized poly(glycine)-modified graphite paste sensor (PGMGPS) was studied through Field emission scanning electron microscopy (FE-SEM). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the active surface area of the working sensors. The optimum pH was determined to be 6.0 in phosphate buffer solution (PBS) of 0.2 M concentration. The analysis of potential scan rate variation revealed that the electro-oxidation of AXN on the electrode surface proceeds through diffusion-controlled kinetics with the transfer of two electrons. The limit of detection (LOD) were assessed to be 0.26 µM by CV, 0.24 µM by DPV, and 0.70 µM by LSV techniques, all exhibiting good linearity of oxidation peak current with the varied concentration of AXN. The developed sensor exhibited high selectivity and sensitivity toward the concurrent analysis with rutin (RTN), a flavonoid glycoside. The productivity of PGMGPS was noticed to be unaltered even in the presence of certain interfering metal ions. Furthermore, the stability, reproducible and repeatable attributes of the designed sensor were assessed and the obtained results are in accordance with the required limits. The performed analyses authenticate the proposed PGMGPS as reliable sensor for the quantification of AXN in food samples.

Flexible photoelectric sensors with high stretchability and easy integration have accelerated the evolution of wearable electronic devices. The CNTs (carbon nanotubes)-based composites are a suitable alternative to the preparation of sensing materials by virtue of the remarkable performance. Hitherto, the preparation process aimed at fabricating the versatile flexible photoelectric devices has been constrained due to the poor charge separation and photoelectric conversion efficiency under the circumstance of extension, bending, or folding. Here, we develop a novel technique involving the in situ polymerization and co-precipitation method to prepare the CNT-PAN (CNT-polyaniline) composite and Ga₂O₃, which are deposited on the surface of sensor, respectively, which consisted of the interdigital Au electrode and flexible PDMS substrate. The study manifests the synergetic transformation of the flexibility and photoelectric property. The modification of PAN improves the stretchability and charge transfer capability via the active functional groups on the polyaniline and strong π–π electrons interaction between CNT and PAN. The introduction of Ga₂O₃ enhances the light–matter interaction. On this basis, the CNT-PAN and Ga₂O₃ are deposited on the surface of sensor, respectively, which consisted of the interdigital Au electrode and flexible PDMS substrate for the sake of enhancing the light–matter interaction. The study manifests that photoconductive property was enhanced by the assembly process. The findings provide enlightenment into the exploration of multi-performance optoelectronic devices.

This study systematically investigates the effects of binder content, carbonyl iron powder (CIP) content, and FeSiAl nanocrystalline powder particle size on the permeability and core loss of soft magnetic composites (SMCs) for power inductor applications. Unlike previous studies that primarily focus on either composition control or magnetic performance optimization, this research integrates both aspects to develop high-performance SMCs with enhanced magnetic efficiency. The permeability and core loss were quantitatively evaluated, and improvements were assessed by comparing different parameter combinations. The optimized composites, incorporating 40–70 wt% CIP and 1.8–5.0 wt% binder, achieved superior permeability (38.2) and low core loss (286 mW/cm³ at 100 kHz), making them highly suitable for high-frequency power inductors. The results demonstrate that optimizing the binder content, CIP ratio, and nanocrystalline FeSiAl powder particle size significantly enhances magnetic properties while maintaining mechanical integrity. This study provides valuable insights into the development of advanced SMCs, offering practical improvements in energy efficiency for modern electronic devices.

The investigation focuses on polymeric nanocomposites based on PVA doped with niobium oxide (Nb₂O₅) and vanadium pentoxide (V₂O₅). The structure of the fabricated nanocomposites was examined via various methods. Morphological analysis revealed that the average particle size of Nb₂O₅ in PVA-Nb₂O₅ is approximately 110 nm, while in PVA-Nb₂O₅-3%V₂O₅, Nb₂O₅ reaches 103 nm, and V₂O₅ particles are dispersed with an average size of 35 nm. Thermal analysis via TGA demonstrated enhanced stability, with the total weight loss decreasing upon filler insertion. The residual mass increased due to the presence of inorganic oxides, with a final residue of 4.9% for pure PVA and increasing with Nb₂O₅ and V₂O₅ doping. Furthermore, optical studies showed an x-axis shifting absorption edge for PVA, which starts at 3.8 eV and lowers to 2.5 eV for PVA-Nb₂O₅-7%V₂O₅ nanocomposite. The indirect band gap decreases for all nanocomposites, reaching 2.85 eV in PVA-Nb₂O₅-7%V₂O₅ nanocomposite, compared to 5.5 eV in PVA. In contrast, the refractive index registers 1.687 in PVA and increases to 2.075 in PVA-Nb₂O₅-7%V₂O₅ nanocomposite. Moreover, dielectric measurements revealed that the dielectric constant rose to 43 in PVA-Nb₂O₅ nanocomposite but fell from approximately 30 for PVA to less than 20 following doping with V₂O₅. The high relative permittivity of Nb2O5 (100) and V₂O₅ (25) suggests their suitability for advanced dielectric applications. AC resistivity measurements showed an increasing trend with frequency, reaching their highest value at PVA-Nb₂O₅-7%V₂O₅. The optical and dielectric analysis of PVA-Nb₂O₅-V₂O₅ nanocomposites obtained unique behavior in line with earlier studies. Thus, the examined nanocomposites present a potentially useful nano-composite for optoelectronic applications.