Developing highly efficient magnetic microwave absorb-ers(MAs)is crucial,and yet challenging for anti-corrosion properties in extremely humid and salt-induced foggy environments.Herein,a dual-oxide shell of ZnO/Al_(2)...Developing highly efficient magnetic microwave absorb-ers(MAs)is crucial,and yet challenging for anti-corrosion properties in extremely humid and salt-induced foggy environments.Herein,a dual-oxide shell of ZnO/Al_(2)O_(3) as a robust barrier to FeSiAl core is introduced to mitigate corrosion resistance.The FeSiAl@ZnO@Al_(2)O_(3) layer by layer hybrid structure is realized with atomic-scale precision through the atomic layer deposition technique.Owing to the unique hybrid structure,the FeSiAl@ZnO@Al_(2)O_(3) exhibits record-high micro-wave absorbing performance in low-frequency bands covering L and S bands with a minimum reflection loss(RLmin)of-50.6 dB at 3.4 GHz.Compared with pure FeSiAl(RLmin of-13.5 dB,a bandwidth of 0.5 GHz),the RLmin value and effective bandwidth of this designed novel absorber increased up to~3.7 and~3 times,respectively.Fur-thermore,the inert ceramic dual-shells have improved 9.0 times the anti-corrosion property of FeSiAl core by multistage barriers towards corrosive medium and obstruction of the electric circuit.This is attributed to the large charge transfer resistance,increased impedance modulus|Z|0.01 Hz,and frequency time constant of FeSiAl@ZnO@Al_(2)O_(3).The research demonstrates a promising platform toward the design of next-generation MAs with improved anti-corrosion properties.展开更多
Zero-index metamaterials(ZIMs)feature a uniform electromagnetic mode over a large area in arbitrary shapes,enabling many applications including high-transmission supercouplers with arbitrary shapes,directionindependen...Zero-index metamaterials(ZIMs)feature a uniform electromagnetic mode over a large area in arbitrary shapes,enabling many applications including high-transmission supercouplers with arbitrary shapes,directionindependent phase matching for nonlinear optics,and collective emission of many quantum emitters.However,most ZIMs reported to date are passive;active ZIMs that allow for dynamic modulation of their electromagnetic properties have rarely been reported.Here,we design and fabricate a magnetically tunable ZIM consisting of yttrium iron garnet(YIG)pillars sandwiched between two copper clad laminates in the microwave regime.By harnessing the Cotton–Mouton effect of YIG,the metamaterial was successfully toggled between gapless and bandgap states,leading to a“phase transition”between a zero-index phase and a single negative phase of the metamaterial.Using an S-shaped ZIM supercoupler,we experimentally demonstrated a tunable supercoupling state with a low intrinsic loss of 0.95 d B and a high extinction ratio of up to 30.63 d B at 9 GHz.We have also engineered a transition between the supercoupling state and the topological one-way transmission state at10.6 GHz.Our work enables dynamic modulation of the electromagnetic characteristics of ZIMs,enabling various applications in tunable linear,nonlinear,quantum,and nonreciprocal electromagnetic devices.展开更多
Environmentally-friendly magnetic metallic absorbers with high-performing antioxidant property,thermal stability,and anticorrosion capability have attracted great attention in real-world applications.A surface modific...Environmentally-friendly magnetic metallic absorbers with high-performing antioxidant property,thermal stability,and anticorrosion capability have attracted great attention in real-world applications.A surface modification technology of magnetic metallic absorbers with dense and inert materials has been an effective strategy to solve the aforesaid problem.Herein,fluorinefree core–shell carbonyl iron-organic silicon absorbers(CI@SiO_(2)/1,1,1,3,3,3-hexamethyl disilazane(HMDS))were fabricated via a facile one-pot synthesis using tetraethyl orthosilicate(TEOS)and HMDS as the precursor of protective layer(SiO_(2)/HMDS),and CI@SiO_(2)/HMDS hybrid reveals its long-term corrosion resistance and excellent microwave absorption performance with a minimum reflection loss value of−44.3 dB and an effective absorption bandwidth of 5.3 GHz at a thin thickness of 2.0 mm after immersion in 5.0 wt.%NaCl acidic solutions for 2,160 h.Meanwhile,CI@SiO_(2)/HMDS hybrid can still achieve the maximum radar cross-sectional(RCS)reduction values about 16.5 dB·m^(2) at the detectionθof 0°.The exceptional microwave absorption performance and structural stability are largely due to the extraordinary wave-transparent property and shielding ability against corrosive medium of SiO_(2)/HMDS hydrophobic protective layer with a contact angle of 132.5°.The research paves the way for the large-scale and batch production of high-performance magnetic metallic absorbers and increases their survivability and reliability in the harsh environments.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51972045,5197021414)the Fundamental Research Funds for the Chinese Central Universities,China(No.ZYGX2019J025)+4 种基金Sichuan Science and Technology Program(No.2020JDRC0015 and No.2020JDRC0045)Sichuan Science and Technology Innovation Talent Project(No.2021JDRC0021)the Vice-Chancellor fellowship scheme at RMIT Universitythe RMIT Micro Nano Research Facility(MNRF)in the Victorian node of the Australian National Fabrication Facility(ANFF)the RMIT Microscopy and Microanalysis Facility(RMMF)to support this work。
文摘Developing highly efficient magnetic microwave absorb-ers(MAs)is crucial,and yet challenging for anti-corrosion properties in extremely humid and salt-induced foggy environments.Herein,a dual-oxide shell of ZnO/Al_(2)O_(3) as a robust barrier to FeSiAl core is introduced to mitigate corrosion resistance.The FeSiAl@ZnO@Al_(2)O_(3) layer by layer hybrid structure is realized with atomic-scale precision through the atomic layer deposition technique.Owing to the unique hybrid structure,the FeSiAl@ZnO@Al_(2)O_(3) exhibits record-high micro-wave absorbing performance in low-frequency bands covering L and S bands with a minimum reflection loss(RLmin)of-50.6 dB at 3.4 GHz.Compared with pure FeSiAl(RLmin of-13.5 dB,a bandwidth of 0.5 GHz),the RLmin value and effective bandwidth of this designed novel absorber increased up to~3.7 and~3 times,respectively.Fur-thermore,the inert ceramic dual-shells have improved 9.0 times the anti-corrosion property of FeSiAl core by multistage barriers towards corrosive medium and obstruction of the electric circuit.This is attributed to the large charge transfer resistance,increased impedance modulus|Z|0.01 Hz,and frequency time constant of FeSiAl@ZnO@Al_(2)O_(3).The research demonstrates a promising platform toward the design of next-generation MAs with improved anti-corrosion properties.
基金Ministry of Science and Technology of the People's Republic of China(2021YFA1401000,2021YFB2801600)National Natural Science Foundation of China(51972044,52021001,62075114,U22A20148)+3 种基金Zhuhai Industry-University Research Collaboration Project(ZH22017001210108PWC)Beijing Municipal Natural Science Foundation(4212050,Z220008)Fundamental Research Funds for the Central Universities(ZYGX2020J005)Sichuan Provincial Science and Technology Department(2019YFH0154,2021YFSY0016,99203070)。
文摘Zero-index metamaterials(ZIMs)feature a uniform electromagnetic mode over a large area in arbitrary shapes,enabling many applications including high-transmission supercouplers with arbitrary shapes,directionindependent phase matching for nonlinear optics,and collective emission of many quantum emitters.However,most ZIMs reported to date are passive;active ZIMs that allow for dynamic modulation of their electromagnetic properties have rarely been reported.Here,we design and fabricate a magnetically tunable ZIM consisting of yttrium iron garnet(YIG)pillars sandwiched between two copper clad laminates in the microwave regime.By harnessing the Cotton–Mouton effect of YIG,the metamaterial was successfully toggled between gapless and bandgap states,leading to a“phase transition”between a zero-index phase and a single negative phase of the metamaterial.Using an S-shaped ZIM supercoupler,we experimentally demonstrated a tunable supercoupling state with a low intrinsic loss of 0.95 d B and a high extinction ratio of up to 30.63 d B at 9 GHz.We have also engineered a transition between the supercoupling state and the topological one-way transmission state at10.6 GHz.Our work enables dynamic modulation of the electromagnetic characteristics of ZIMs,enabling various applications in tunable linear,nonlinear,quantum,and nonreciprocal electromagnetic devices.
基金supported by the National Natural Science Foundation of China(Nos.51972045 and 5197021414)the Fundamental Research Funds for the Chinese Central Universities,China(No.ZYGX2019J025)+2 种基金Sichuan Science and Technology Program(Nos.2020JDRC0015 and 2020JDRC0045)the Natural Science Foundation of Sichuan(No.2022NSFSC0347)Sichuan Science and Technology Innovation Talent Project(No.2021JDRC0021).
文摘Environmentally-friendly magnetic metallic absorbers with high-performing antioxidant property,thermal stability,and anticorrosion capability have attracted great attention in real-world applications.A surface modification technology of magnetic metallic absorbers with dense and inert materials has been an effective strategy to solve the aforesaid problem.Herein,fluorinefree core–shell carbonyl iron-organic silicon absorbers(CI@SiO_(2)/1,1,1,3,3,3-hexamethyl disilazane(HMDS))were fabricated via a facile one-pot synthesis using tetraethyl orthosilicate(TEOS)and HMDS as the precursor of protective layer(SiO_(2)/HMDS),and CI@SiO_(2)/HMDS hybrid reveals its long-term corrosion resistance and excellent microwave absorption performance with a minimum reflection loss value of−44.3 dB and an effective absorption bandwidth of 5.3 GHz at a thin thickness of 2.0 mm after immersion in 5.0 wt.%NaCl acidic solutions for 2,160 h.Meanwhile,CI@SiO_(2)/HMDS hybrid can still achieve the maximum radar cross-sectional(RCS)reduction values about 16.5 dB·m^(2) at the detectionθof 0°.The exceptional microwave absorption performance and structural stability are largely due to the extraordinary wave-transparent property and shielding ability against corrosive medium of SiO_(2)/HMDS hydrophobic protective layer with a contact angle of 132.5°.The research paves the way for the large-scale and batch production of high-performance magnetic metallic absorbers and increases their survivability and reliability in the harsh environments.