High-Quality Ferromagnet Fe₃GeTe₂ for High-Efficiency Electromagnetic Wave Absorption and Shielding with Wideband Radar Cross Section Reduction

Abstract

A high-quality Fe3GeTe2 single crystal with good electrical, magnetic, and electromagnetic wave absorption and shielding properties was prepared in a large quantity (10 g level) by solid-phase sintering and recrystallization method, which would promote its in-depth research and practical application. It has good room-temperature electrical properties with a mobility of 42 cm2/V·s, a sheet (bulk) carrier concentration of +1.64 × 1018 /cm2 (+3.28 × 1020 /cm3), and a conductivity of 2196.35 S/cm. Also, a Curie temperature of 238 K indicates the high magnetic transition temperature and a paramagnetic Curie temperature of 301 K shows the large ferromagnetic–paramagnetic transition zone induced by the residual short-range ferromagnetic domains. Particularly, Fe3GeTe2 is in a loosely packed state when used as a loss agent; the electromagnetic wave absorption with a reflection loss of −34.7 dB at 3.66 GHz under thin thickness was shown. Meanwhile, the absorption band can be effectively regulated by varying the thickness. Moreover, Fe3GeTe2 in a close-packed state exhibits terahertz shielding values of 75.1 and 103.2 dB at very thin thicknesses of 70 and 380 μm, and the average shielding value is higher than 47 dB, covering the entire bandwidth from 0.1 to 3.0 THz. Furthermore, by using Fe3GeTe2 as a patch, the wideband radar cross-section can be effectively reduced by up to 33 dBsm. Resultantly, Fe3GeTe2 will be a promising candidate in the electromagnetic protection field.

Defect-Enriched Iron Oxide from Industrial Waste for Lithium Oxygen Batteries with High Economic Efficiency and Industrial Feasibility

“…The Fe 2p spectral lines for α-Fe 2 O 3 and γ-Fe 2 O 3 pose narrow peaks and shake-up satellite peaks situated at 718.9 and 732.9 eV. By comparison, the Fe 2p spectral line for Fe 3 O 4 reveals broad peaks at ∼710.7 and ∼724.1 eV, indicating that the coexistence of Fe 3+ and Fe 2+ , and the shoulder at ∼708 eV of Fe 3 O 4 belongs to Fe 2+ . , As shown in Table , the atomic ratio of Fe 3+ /Fe 2+ is 1.98, closing to the Fe 3 O 4 stoichiometric value (2.0). This demonstrates the phase transition from α-Fe 2 O 3 to Fe 3 O 4 has been successfully completed through the thermal treatment in a reduction atmosphere.…”

2D Magnetic Semiconductor Fe3GeTe2 with Few and Single Layers with a Greatly Enhanced Intrinsic Exchange Bias by Liquid-Phase Exfoliation

“…High-quality FGT bulk crystals with high purity and crystallinity (Figure S1) were synthesized based on our previous work. 11 Based on this, highstructural-integrity, large-size, high-yield, and high-output FGT nanoflakes with a natural ferromagnetic/antiferromagnetic heterostructure were obtained by the TS-LPE method, and a schematic illustration is shown in Figure 1. Slicing bulk crystals, weakening vdW forces, and then exfoliating FGT into 2D nanoflakes by ultrasonic cavitation without the introduction of intermediates 61,62 are beneficial for application in spintronics and topological devices.…”

“…High-quality FGT bulk crystals with high purity and crystallinity (Figure S1) were synthesized based on our previous work . Based on this, high-structural-integrity, large-size, high-yield, and high-output FGT nanoflakes with a natural ferromagnetic/antiferromagnetic heterostructure were obtained by the TS-LPE method, and a schematic illustration is shown in Figure .…”

“…Then, shining platelike bulk crystals were synthesized by our previously reported solid-phase sintering and recrystallization method. 11 A quality analysis of the synthesized crystals is shown in Figure S1.…”

“…vdW magnetic materials − have aroused extensive interest because of their wide applications in spintronics, information processing, magnetic storage, etc. Fe 3 GeTe 2 (FGT) with 2D intrinsic ferromagnetism, a higher Curie temperature ( T C ), − and slower oxidation process , has become a promising candidate for next-generation 2D magnetic devices. Since FGT was reported in 2006, extensive research has been performed in simulation calculations and structural design based on the visualization and manipulation of magnetic domains, − magnetically controllable regulation, − heterostructure correlation magnetism properties, − and others. − For example, the stripy domains, double-walled domains, and bubble domains in FGT were directly observed with the nickel tip of a scanning tunneling microscope and realized the transition between domains .…”