Optical control of magnetic anisotropy in ferromagnetic (FM) metals via non-thermal effects offers an intriguing route for the ultrafast magnetization control. Here, we report on strong modification of exchange-coupling induced uniaxial magnetic anisotropy (UMA) in Fe/CoO below the Néel temperature of CoO owing to the charge transfer excited by ultrafast laser pulses. This UMA modification by nonthermal effects is manifested as much smaller frequencies of the Fe spin precession in the initial 100-ps time range under the 400-nm pump with charge transfer excitation, compared to the 800-nm pump with pure thermal effects. From the time-dependent frequency shift under a moderate pump fluence of 0.5 mJ/cm2, we determined the magnitude of the UMA attenuation with a highest value of more than 1000 Oe in a duration of 100 ps. The strong UMA attenuation is attributed to the large suppression of the interface exchange coupling as a result of the diminishment of antiferromagnetic (AFM) spin order in CoO. Our results give insights into the ultrafast spin modulation in AFM CoO dominated by the electronic process, which can be utilized for efficient driving of the coherent spin motion in the proximate FM metal exchange coupled to CoO.
Methyl formate (MF) is one of the most important chemical commodities, which has a wide range of applications. Due to environmental friendliness, mild reaction conditions, and easy operations, electrosynthesis of MF has garnered increasing attention in recent years. In this work, we reported an electrosynthesis route toward MF in a halide-containing methanol solution. The thorough mechanistic investigations point out that electrosynthesis of MF is accomplished by instant reaction between aldehyde from anodic methanol oxidation, and methoxy bromide (CH
Through the application of partial discharge detection technology, weak partial discharge signals can be detected to ensure the normal stability of the insulation structure of distribution transformers. In this paper, the detection methods of partial discharge such as pulse current method, ultrasonic detection method, UHF detection method, dissolved gas analysis method, and transient-to-ground voltage detection method are technically sorted out and summarized. And put forward the views on the future development trend of partial discharge detection technology, and the specific ideas of follow-up research.
Organic fuel is the main factor affecting the morphology, structure and catalytic activity of metal oxide materials in solution combustion synthesis (SCS). However, due to the interference of other factors in SCS (Such as PH and fuel ratio), the specific effect of organic fuels on SCS is still questionable. In this work, we systematically select organic fuels (Ethylene glycol, glycine, lactose, sucrose and citric acid) to successfully prepare hierarchically porous MgCo2O4 nanomaterials by a simple one-step SCS. MgCo2O4 prepared with citric acid as fuel (CA-MCO) has the largest specific surface area and the most abundant pore structure. And the porous CA-MCO exhibited the best catalytic properties that the THTD of AP decreased by 206.06 °C, the activation energy (Ea) decreased by 104.58 kJ·mol-1, and the reaction rate (k) increased by 2.49 s-1. A possible catalytic mechanism for the thermal decomposition of AP was also proposed based on TG-MS and Hall effect tests. Finally, CA-MCO was applied to AP/HTPB-based composite solid propellants (CSPs), and the results showed that the introduction of CA-MCO significantly shortened the ignition delay time of the CSPs (From 29 ms to 8 ms), indicating its potential application in the CSPs.
Distribution of trigonal prism capped with three half-octahedra (orange clusters), archimedean anti-prism (green ones) and icosahedron (blue ones) clusters in Pd82Si18 at different temperature (a) 900 K, (b) 1216 K. (c) Connection way of different clusters, and pink ones are the sharing atoms.
Burdock is native to Europe and Asia and rich in many functional ingredients, including biomacromolecule polysaccharide inulin. The prebiotic fructan inulin can provide energy to organisms
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