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Absorption (electromagnetic radiation)

About: Absorption (electromagnetic radiation) is a research topic. Over the lifetime, 76674 publications have been published within this topic receiving 1381221 citations.


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Journal ArticleDOI
TL;DR: In this paper, a hierarchical sandwich microstructure of two-dimensional (2D) Ti3C2Tx MXene flakes is proposed for the design of a novel electromagnetic wave absorber, which not only provides an effective route for extending further the applications of 2D MXene materials in the field of electromagnetic wave absorption.
Abstract: Ti3C2Tx MXenes modified with in situ grown carbon nanotubes (CNTs) are fabricated via a simple catalytic chemical vapor deposition (CVD) process. The as-prepared Ti3C2Tx/CNT nanocomposites show that one-dimensional (1D) carbon nanotubes are uniformly distributed in the interlayers of two-dimensional (2D) Ti3C2Tx MXene flakes. Compared with the pristine Ti3C2Tx MXenes, the hierarchical sandwich microstructure makes a contribution to the excellent electromagnetic wave absorption performance in the frequency range of 2–18 GHz, including higher absorption intensity (the minimum reflection coefficient reaches −52.9 dB, ∼99.999% absorption), broader effective absorption bandwidth (4.46 GHz), lower filler loading (35 wt%) and thinner thickness (only 1.55 mm). In addition, with the adjustment of thickness from 1.55 to 5 mm, the effective absorption bandwidth can reach up to 14.54 GHz (3.46–18 GHz). Different absorption mechanisms mainly based on polarization behaviors and conductivity loss are discussed. This work not only proposes the design of a novel electromagnetic wave absorber, but also provides an effective route for extending further the applications of 2D MXene materials in the field of electromagnetic wave absorption.

309 citations

Journal ArticleDOI
TL;DR: A comprehensive review on the recent research progress of nanomaterials for microwave absorption, including the basic mechanism of microwave absorption (e.g., dielectric loss, magnetic loss coupling), measurement principle, fundamental analysis, performance evaluation, common interaction pathways: Debye relaxation, Eddy current loss, natural resonance, size and shape factors), and the advances and performance review in microwave absorption using various nanommaterials, such as carbon nanotubes, carbon fibers, graphenes, oxides, sulfides, phosphides, carbides, polymers and metal organic

308 citations

Journal ArticleDOI
TL;DR: In this article, the microwave absorption properties of carbon-coated magnetic metal NPs were investigated in terms of impedance matching, core/shell structure and nanosize effects, and a minimum reflection loss (RL) value of −43.4 dB at a thickness of 2.3 mm.
Abstract: Co/C nanoparticles (NPs) with a size of 45 nm have been prepared by an arc plasma method under a mixed methane and argon atmosphere. They display a uniform carbon shell of 3 nm in thickness and have a low graphitization degree. The saturation magnetization (MS) and coercivity (HC) of the NPs are 159.9 emu g−1 and 275.7 Oe, respectively. The microwave absorption properties of the Co/C NPs mixed with paraffin wax (PW) at 25, 50 and 75 wt% NPs have been investigated in the range of 2–18 GHz. The Co/C-PW composite with 50 wt% NPs exhibits the best microwave absorption performance. It has a minimum reflection loss (RL) value of −43.4 dB at a thickness of 2.3 mm, and the absorption bandwidth for RL ≤ −20 dB is as large as 7.2 GHz, which is the highest value among the reported Co-based absorbers. The high microwave absorption performance is interpreted in terms of impedance matching, core/shell structure and nanosize effects. The carbon-coated magnetic metal NPs prepared by methane plasma arc are potential microwave absorbers with strong absorption intensity and wide absorption bandwidth.

308 citations

Journal ArticleDOI
TL;DR: A Ti3 C2 Tx MXene-based photonic diode that breaks time-reversal symmetry to achieve nonreciprocal transmission of nanosecond laser pulses is demonstrated and is found to show higher threshold for light-induced damage with up to 50% increase in nonlinear transmittance.
Abstract: MXenes comprise a new class of 2D transition metal carbides, nitrides, and carbonitrides that exhibit unique light-matter interactions. Recently, 2D Ti3 CNTx (Tx represents functional groups such as OH and F) was found to exhibit nonlinear saturable absorption (SA) or increased transmittance at higher light fluences, which is useful for mode locking in fiber-based femtosecond lasers. However, the fundamental origin and thickness dependence of SA behavior in MXenes remain to be understood. 2D Ti3 C2 Tx thin films of different thicknesses are fabricated using an interfacial film formation technique to systematically study their nonlinear optical properties. Using the open aperture Z-scan method, it is found that the SA behavior in Ti3 C2 Tx MXene arises from plasmon-induced increase in the ground state absorption at photon energies above the threshold for free carrier oscillations. The saturation fluence and modulation depth of Ti3 C2 Tx MXene is observed to be dependent on the film thickness. Unlike other 2D materials, Ti3 C2 Tx is found to show higher threshold for light-induced damage with up to 50% increase in nonlinear transmittance. Lastly, building on the SA behavior of Ti3 C2 Tx MXenes, a Ti3 C2 Tx MXene-based photonic diode that breaks time-reversal symmetry to achieve nonreciprocal transmission of nanosecond laser pulses is demonstrated.

308 citations

Journal ArticleDOI
TL;DR: A method for measurement of b(abs) uses a piece of opal glass to integrate light scattered by particles collected on Nuclepore filters and shows it is accurate to well within an order of magnitude for particles of radius larger than 0.1 microm.
Abstract: Recent models predict that the effect of atmospheric aerosol particles on global temperature depends in part on b(abs,)or on n(2), where b(abs) is the aerosol absorption coefficient, and n(2) is the imaginary part of the aerosol refractive index for radiation in visible wavelengths Satisfactory techniques for measuring b(abs) have yet to be developed A method for measurement of b(abs) is described and discussed The apparatus uses a piece of opal glass to integrate light scattered by particles collected on Nuclepore filters It is quite mobile, inexpensive, and can be calibrated Analysis of the errors inherent in the measurement shows it is accurate to well within an order of magnitude for particles of radius larger than 01 microm

308 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2022185
20213,106
20202,866
20192,953
20182,876
20172,679