ADVANCED MATERIALS
·
2023
·Vol. 35
·期 36
·2302568
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IF 29.4
Yueshen Wu,Yuxiong Hu,Cong Wang,Xiang Zhou,Xiaofei Hou,Wei Xia,Yiwen Zhang,Jinghui Wang,Yifan Ding,Jiadian He,Peng Dong,Song Bao,Jinsheng Wen,Yanfeng Guo,Kenji Watanabe,Takashi Taniguchi,Wei Ji,Zhu-Jun Wang,Jun Li
Fe 3 GeTe 2 have proven to be of greatly intrigue. However, the underlying mechanism behind the varying Curie temperature ( T c ) values remains a puzzle. This study explores the atomic structure of Fe 3 GeTe 2 crystals exhibiting T c values of 160, 210, and 230 K. The elemental mapping reveals a Fe-intercalation on the interstitial sites within the van der Waals gap of the high- T c (210 and 230 K) samples, which are observed to have an exchange bias effect by electrical transport measurements, while Fe intercalation or the bias effect is absent in the low- T c (160 K) samples. First-principles calculations further suggest that the Fe-intercalation layer may be responsible for the local antiferromagnetic coupling that gives rise to the exchange bias effect, and that the interlayer exchange paths greatly contribute to the enhancement of T c . This discovery of the Fe-intercalation layer elucidates the mechanism behind the hidden antiferromagnetic ordering that underlies the enhancement of T c in Fe 3 GeTe 2 .
研究领域:
凝聚态物理
·
磁性材料
·
二维材料
·
自旋电子学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Guanghao Li,Suping Ma,Zhuo Li,Yawen Zhang,Jianglin Diao,Lun Xia,Zhiwei Zhang,Yi Huang
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.
研究领域:
材料科学
·
电磁学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2022
·
IF 18.027
Suping Ma,Guanghao Li,Zhuo Li,Yawen Zhang,Haolin Lu,Zhansheng Gao,Jinxiong Wu,Guankui Long,Yi Huang
A 2D van der Waals (vdW) magnet can get rid of the constraints of lattice matching and compatibility and then create a variety of vdW heterostructures, which provides a opportunity for spintronic devices. However, the ability to reliably exfoliate large, high-quality vdW ferromagnetic Fe3GeTe2 (FGT) nanoflakes in scaled-up production is severely limited. Herein, an efficient and stable three-stage sonication-assisted liquid-phase exfoliation was developed for mass preparation of high-structural-integrity few- and single-layer FGT nanoflakes with a greatly enhanced intrinsic exchange bias. The three stages include slicing crystals, weakening interlayer vdW forces, and using ultrasonic cavitation. The highest yield of FGT nanoflakes is 22.3 wt % with single layers accounting for 6%. The size is controllable, and several micrometers, tens of micrometers, and a maximum of 103 μm are available. The 200 mg level output has overcome the limitations of mechanical exfoliation and molecular beam epitaxy in economically amplificated production. An intrinsic exchange bias is observed in the restacked nanoflakes due to the magnetic proximity on the interface of the FGT/natural surface oxide layer. The material reaches 578 Oe (2 K) and 2300 Oe after further oxidation, at least 250% higher than other precisely tailored vdW magnetic heterostructures. In addition, the unusual semiconductivity of the liquid-phase exfoliated FGT nanoflakes is reported. This work skillfully utilizes oxidation to enhance the potential of FGT for large-scale spintronics, optoelectronics, efficient data storage, and various extended applications, and it is beneficial for exfoliating other promising magnetic vdW materials.
研究领域:
材料科学
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自旋电子学
·
纳米技术
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 15
·2210578
·
IF 19
Guanghao Li,Suping Ma,Zhuo Li,Yawen Zhang,Yishu Cao,Yi Huang
Fe 3 GeTe 2 provides an ideal system for the study of itinerant ferromagnetism. However, the Curie temperature (Tc) below room temperature limits its further in-depth research and wide applications. Here, the Tc of 224 K for Fe 3 GeTe 2 is greatly increased to 496 K for Fe 3 GeTe 2 /FeTe 2 /Fe 3 Ge by temperature-induced self-decomposition doping, contributing to improve the electromagnetic response for enhancing the absorption strength and bandwidth and boosting application potentials at higher temperatures. Then, to achieve the multispectral compatible strong absorption, room temperature ferromagnetic dielectric graphene@Fe 3 GeTe 2 /FeTe 2 /Fe 3 Ge absorber with 3D porous network structure is prepared by synergistic self-assembly. It has high Tc of 443 K with strong electromagnetic synergistic loss, achieving reflection loss of −61 dB at 12.6 GHz. Moreover, its absorption loss in the terahertz band (0.1–1.6 THz) is 76 dB, and the average loss is greater than 50.4 dB. Furthermore, the absorber is very potential as stealth skin to efficiently reduce satellite RCS with a multi-angle and multi-band manner in the gigahertz and terahertz bands, thus achieving the purpose of stealth. Compared with the reported conventional absorbers, the absorber has a multispectral compatible strong absorption performance covering gigahertz and terahertz bands, thus very promising for electromagnetic protection of electromagnetic communication and space vehicles.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Materials Horizons
·
2021
·Vol. 8
·期 12
·3306-3314
·
IF 13.266
Liang Hu,Jian Zhou,Zhipeng Hou,Weitao Su,Bingzhang Yang,Lingwei Li,Mi Yan
The demand for high-performance spintronic devices has boosted intense research on the manipulation of magnetism in van der Waals (vdW) magnets. Despite great efforts, robust ferromagnetic transitions above room temperature still face significant hurdles. Strain engineering can reversibly regulate magnetic exchange, but the degree of regulation is still impractical for most magnetic applications. Hereby we employ a large-strain transferrer to produce tunable strains of up to 4.7%, which induces authentic room-temperature ferromagnetism in large-area Fe3GeTe2 nanoflakes with 20-fold improvement in magnetization. The record increment of the Curie temperature (TC) of well above 400 K originates from the strain-enhanced magnetic anisotropy and excellent magnetoelastic coupling. The correlation between the emerging ferromagnetism and Raman spectral evolution is also established, which complements well the TC phase diagram in a large-strain region. In addition, an unusual exchange bias effect with a vertical magnetization shift is tracked for the first time upon bending, which reveals the hidden competition between antiferromagnetic and ferromagnetic coupling. The reversible strain manipulation of single-domain ferromagnetic order in a single nanoflake further opens up a route to develop low-power wearable spintronic devices. The findings here provide vast opportunities to exploit the possibility of practical applications of more vdW magnets.
研究领域:
凝聚态物理
·
材料科学
·
纳米科技
·
自旋电子学
·
柔性电子学
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）