Materials Technology (United Kingdom)

Radiation-induced structural damage in natural zircon, known as metamictization, alters its crystallinity and affects its high-pressure behavior. Previous studies report a wide range of phase transition pressures (19.7–28.6 GPa) for natural zircon, likely due to various metamictization. To address this, we first heated natural zircon at 1673 K and found its structure restored and then conducted pressure-induced phase transition of heat-treated natural zircon and synthesized zircon by Raman spectroscopy combined with diamond anvil cells (DACs). Our experiments reveal that the phase transition pressure of heat-treated natural zircon aligns with synthesized zircon at approximately 26.8 GPa. Furthermore, we established the relationship between SiO4 vibrational frequency (v3) and temperature–pressure (300–800 K and 0–18 GPa), yielding ΔvT (cm–1) = −4.97 × 10–6(T – T0)2 – 0.03(T – T0), and P (GPa) = [Δv3(P,T) – ΔvT] × 5.13–1. Calibrated by heat-treated natural zircon, we successfully determined the crystallization and dissolution conditions of ammonium fluorosilicate in a hydrothermal DAC.

Advancement of room-temperature ultraviolet (UV) and near-UV photodetectors is crucial for the realization of next-generation optoelectronic interconnects. Semiconductors namely zinc oxide (ZnO) and gallium oxide (Ga2O3) have garnered significant attention due to their exceptional physical properties, availability, and cost-effectiveness. The ultra-wide bandgap of Ga2O3 (∼4.7 eV) enables intrinsic sensitivity to the deep UV radiation, whereas the wide bandgap of ZnO (∼3.37 eV) along with its high exciton binding energy (∼60 meV) that promote efficient excitonic emission at room temperature and can record a UV response under ambient conditions. Therefore, it is possible to sense deep UV along with the UV at room temperature by combining both these materials. Hence, the present study reports the combination of these materials in the form of epistructures, namely, ZnO/Ga2O3/ZnO deposited on n-Si substrates using pulsed laser deposition. The epistructures were characterized structurally, optically and electrically using the respective technique for the quality. The optimized heterostructures were used to fabricate single-pixel photodetectors (500 μm diameter each) following a robust and scalable fabrication process. A variation in transport characteristics recorded under dark and near-UV (403 nm) illumination confirmed its UV detection capability. The electrical measurements carried across such multiple devices revealed excellent uniformity in UV detection and operational stability, underscoring the reliability of both, i.e., synthesis and fabrication processes followed. For 403 nm of excitation wavelength with a minimum intensity of 5000 lux, the devices operated at 2 V demonstrate a photoresponsivity of 0.0155 A/lux, an external quantum efficiency of 0.045, and a specific detectivity of 2.5 × 106 V/lux. To explain the results, photodetection mechanism is proposed based on the Anderson model, which is extended as per the epistructures used. The results reported herewith highlight potential use of ZnO/Ga2O3/ZnO epistructures as one of the conceivable approaches to enable next-generation UV photodetectors and interconnect technologies.

Since E-glass fiber-reinforced epoxy composites have low specific strength, stiffness, and modulus, they have long been indispensable in various applications. By substituting 4% by weight and 8% by weight of the volumes for the hand layup process, this study aims to observe how titanium oxide filler material affects the mechanical characteristics of E-Glass fiber-reinforced polymer. The impact of glass fiber on mechanical properties, including density, flexural strength, breaking strength, tensile strength, and hardness, has been investigated, and SPSS-Scheff has been used to analyze the results. The hybrid composite material, comprising epoxy, 8% GF, and 8% TiO2, exhibits a maximum hardness (Shore D) of 76.2, an ultimate tensile strength of 57.5 MPa, a fracture strength of 14.75 MPa, and an impact strength of 1000 MPa. The addition of Epoxy+ (4%) GF and Epoxy+(8%) GF+8%TiO2 has decreased the flexural strength. In actuality, the composites have a higher density than epoxy plus 4% TiO2. The p-values of 0.003, <0.001, 0.002, <0.001, 0.003, 0.026 for hardness, impact strength, flexural strength, tensile strength, fracture stress (σ fracture), Ultimate Tensile Strength (σ UTS), and true density, respectively, verify the statistically significant differences.

Peptide self-assembly is a promising process in which the conformations formed during dynamic stages play a crucial role in determining the resulting self-assembly morphologies and structural parameters. These unique conformations also hold potential for the de novo design of supramolecular peptide nanomaterials with tailored properties. In this work, we explore the impact of incorporating an α-helix neuropeptide Y fragment (NPY21-27) into amyloid peptide EFFE, focusing on its influence on β-sheet self-assembly. Microscopic imaging and spectroscopic analyses reveal that W2 and W4 peptides form twisted nanofibers based on β-sheet structures, with W4 displaying periodic helical structures. The charged amino acids promote a pH-dependent self-assembly, accompanied by ion coordination behaviors. Notably, the chirality modulation between EFFE and NPY21-27 in W2 induces a structural transition from twisted nanofibers to nanotubes, influenced by molecular orientation and spatial alignment. These findings provide a foundation for rational design of peptide nanomaterials with controlled conformations and structures.

The sluggish kinetics of anode oxygen evolution is a key factor limiting the water-splitting hydrogen production efficiency. Unlike conventional optimization approaches, this study investigates low-symmetry complex ions [Fe(qcq)(CN)3]- (Hqcq = 8-(2-quinolin-2-ylcarboxamido)quinoline) as catalytic precursors for the reaction. This complex ion is utilized for its unique coordination configuration, expected to enhance the metal sites' intrinsic catalytic activity. The results show that when the MOF-like (metal organic frameworks) material constructed by [Fe(qcq)(CN)3]- and nickel salt is loaded on multiwalled carbon nanotubes, it exhibits remarkable enhanced oxygen evolution catalytic performance. By adjusting the loading amount on CNTs, the optimal catalytic performance in 1 M KOH was attained when the mass fraction of CNTs was set at 60%. The overpotential at a current density of 10 mA is only 215 mV, and the Tafel slope is as low as 53.92 mV dec-1. Further research reveals an extraordinary catalytic mechanism: the qcq ligand on the iron site leaches and then recoordinates with nickel. Density functional theory calculations demonstrate that ligand participation induces coordination configuration optimization of Ni2+ active sites, resulting in enhanced oxygen evolution reaction performance. This work provides insights into special coordination effects in nonprecious metal-based oxygen evolution catalysts and strategies for their optimization.