Formaldehyde (FA) long term exposure leads to abnormal pulmonary function and small airway obstruction of the patients. Hydrogen sulfide (HS) is one of the recognized gaseous transmitters involved in a wide range of cellular functions. It is unknown the involvement of HS in FA-induced lung injury.
View Article and Find Full Text PDFInnovation (Camb)
September 2024
The topological Hall effect (THE) is the transport response of chiral spin textures and thus can serve as a powerful probe for detecting and understanding these unconventional magnetic orders. So far, the THE is only observed in either noncentrosymmetric systems where spin chirality is stabilized by Dzyaloshinskii-Moriya interactions, or triangular-lattice magnets with Ruderman-Kittel-Kasuya-Yosida-type interactions. Here, a pronounced THE is observed in a Fe-Co-Ni-Mn chemically complex alloy with a simple face-centered cubic (fcc) structure across a wide range of temperatures and magnetic fields.
View Article and Find Full Text PDFLunar glasses with different origins act as snapshots of their formation processes, providing a rich archive of the Moon's formation and evolution. Here, we reveal diverse glasses from Chang'E-5 (CE-5) lunar regolith, and clarify their physical origins of liquid quenching, vapor deposition and irradiation damage respectively. The series of quenched glasses, including rotation-featured particles, vesicular agglutinates and adhered melts, record multiple-scale impact events.
View Article and Find Full Text PDFPhysical aging is a long-lasting research hot spot in the glass community, yet its long-term effects remain unclear because of the limited experimental time. In this study, we discover the extraordinary aging effects in five typical lunar glassy particles with diameters ranging from about 20 to 53 micrometers selected from Chang'e-5 lunar regolith. It is found that geological time scales' aging can lead to unusually huge modulus enhancements larger than 73.
View Article and Find Full Text PDFThe prevalence of wide-bandgap (WBG) semiconductors allows modern electronic devices to operate at much higher frequencies. However, development of soft magnetic materials with high-frequency properties matching the WBG-based devices remains challenging. Here, a promising nanocrystalline-amorphous composite alloy with a normal composition Fe Co Mo Cu Nb Si B in atomic percent is reported, which is producible under industrial conditions, and which shows an exceptionally high permeability at high frequencies up to 36 000 at 100 kHz, an increase of 44% compared with commercial FeSiBCuNb nanocrystalline alloy (25 000 ± 2000 at 100 kHz), outperforming all existing nanocrystalline alloy systems and commercial soft magnetic materials.
View Article and Find Full Text PDFHow glasses relax at room temperature is still a great challenge for both experimental and simulation studies due to the extremely long relaxation time-scale. Here, by employing a modified molecular dynamics simulation technique, we extend the quantitative measurement of relaxation process of metallic glasses to room temperature. Both energy relaxation and dynamics, at low temperatures, follow a stretched exponential decay with a characteristic stretching exponent β = 3/7, which is distinct from that of supercooled liquid.
View Article and Find Full Text PDFHigh saturation magnetic flux density (B ) of soft magnetic materials is essential for increasing the power density of modern magnetic devices and motor machines. Yet, increasing B is always at the expense of high coercivity (H ), presenting a general trade-off in the soft magnetic material family. Here, superior comprehensive soft magnetic properties, i.
View Article and Find Full Text PDFGlasses have markedly different stability around their glass transition temperature (), and metallic glasses (MGs) are conventionally regarded as metastable compared to other glasses such as silicate glass or amber. Here, we show an aging experiment on a Ce-based MG around its (~0.85) for more than 17 years.
View Article and Find Full Text PDFMetallic , a three-dimensional (3D) biomimetic structure made of metallic glass, is formed via laser patterning: Blooming, closing, and reversing of the metallic can be controlled by an applied magnetic field or by manual reshaping. An array of laser-crystallized lines is written in a metallic glass ribbon. Changes in density and/or elastic modulus due to laser patterning result in an appropriate size mismatch between the shrunken crystalline regions and the glassy matrix.
View Article and Find Full Text PDFThe G-phase, a new metastable phase with its potential energy sitting right in the middle of the glass and crystal, was recently discovered in some simulations when the molten metallic liquid was quenched down to room temperature. In comparison with ordinary glass, the G-phase has a more ordered short-range structure but a similarly disordered long-range structure. The question is whether the G-phase can be termed a new type of glass.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2021
By decreasing the rate of physical vapor deposition, ZrCuAl metallic glasses with improved stability and mechanical performances can be formed, while the microscopic structural mechanisms remain unclear. Here, with scanning transmission electron microscopy and high-energy synchrotron X-ray diffraction, we found that the metallic glass deposited at a higher rate exhibits a heterogeneous structure with compositional fluctuations at a distance of a few nanometers, which gradually disappear on decreasing the deposition rate; eventually, a homogeneous structure is developed approaching ultrastability. This microscopic structural evolution suggests the existence of the following two dynamical processes during ultrastable metallic glass formation: a faster diffusion process driven by the kinetic energy of the depositing atoms, which results in nanoscale compositional fluctuations, and a slower collective relaxation process that eliminates the compositional and structural heterogeneity, equilibrates the deposited atoms, and strengthens the local atomic connectivity.
View Article and Find Full Text PDFDetermination and conceptualization of atomic structures of metallic glasses or amorphous alloys remain a grand challenge. Structural models proposed for bulk metallic glasses are still controversial owing to experimental difficulties in directly imaging the atom positions in three-dimensional structures. With the advanced atomic-resolution imaging, here we directly observed the atomic arrangements in atomically thin metallic glassy membranes obtained by vapor deposition.
View Article and Find Full Text PDFCrack propagation is the major vehicle for material failure, but the mechanisms by which cracks propagate remain longstanding riddles, especially for glassy materials with a long-range disordered atomic structure. Recently, cavitation was proposed as an underlying mechanism governing the fracture of glasses, but experimental determination of the cavitation behavior of fracture is still lacking. Here, we present unambiguous experimental evidence to firmly establish the cavitation mechanism in the fracture of glasses.
View Article and Find Full Text PDFStretchable electrodes are essential components for wearable electronics. However, the stretchability of the electrodes is often achieved with the sacrifice of electronic conductivity along with huge variation in resistance. In this work, stretchable metallic glass electrodes (MG-electrodes) that have both high electronic conductivity and excellent electronic stability are developed.
View Article and Find Full Text PDFSince their discovery in 1960, metallic glasses based on a wide range of elements have been developed. However, the theoretical prediction of glass-forming compositions is challenging and the discovery of alloys with specific properties has so far largely been the result of trial and error. Bulk metallic glasses can exhibit strength and elasticity surpassing those of conventional structural alloys, but the mechanical properties of these glasses are critically dependent on the glass transition temperature.
View Article and Find Full Text PDFFlexible and stretchable nanostructures have broad technological applications. Although nanostructures synthesized with metallic glasses, the alloys being of amorphous atomic structure, exhibit superior properties, they are typically too rigid to be used as flexible materials with existing synthesis techniques. In this study we report periodic and crumpled metallic glass nanostructures that can accommodate a large amount of stretching.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2018
The origin of dramatic slowing down of dynamics in metallic glass-forming liquids toward their glass transition temperatures is a fundamental but unresolved issue. Through extensive molecular dynamics simulations, here we show that, contrary to the previous beliefs, it is not local geometrical orderings extracted from instantaneous configurations but the intrinsic correlation between configurations that captures the structural origin governing slow dynamics. More significantly, it is demonstrated by scaling analyses that it is the correlation length extracted from configuration correlation rather than dynamic correlation lengths that is the key to determine the drastic slowdown of supercooled metallic liquids.
View Article and Find Full Text PDFAlthough the structure and dynamics of metallic glass-forming liquids have been extensively investigated, studies of the pressure effects are rare. In the present study, the structural and dynamical properties of a ternary metallic liquid are systematically studied via extensive molecular dynamics simulations. Our results clearly show that, like isobaric cooling, isothermal compression could also slow down the dynamics of metallic liquid, leading to glass formation.
View Article and Find Full Text PDFA ternary metallic glass-forming liquid is found to be not strongly correlating thermodynamically, but its average dynamics, dynamic heterogeneities including the high order dynamic correlation length, and static structure are still well described by thermodynamic scaling with the same scaling exponent γ. This may indicate that the metallic liquid could be treated as a single-parameter liquid. As an intrinsic material constant stemming from the fundamental interatomic interactions, γ is theoretically predicted from the thermodynamic fluctuations of the potential energy and the virial.
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