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Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 517-532页

作者： Kaili Zhang Yuefeng Yan Zhen Wang Guansheng Ma dechang jia Xiaoxiao Huang Yu Zhou State Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT Key Laboratory of Advanced Structural‑Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)*** on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible ***,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted *** composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA *** results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural ***,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy *** study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism.

关键词： Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching

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Enhanced mechanical properties and thermal shock resistance of Si_2BC_3N ceramics with SiC coated MWCNTs

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Journal of Advanced Ceramics 2019年第1期8卷 121-132页

作者： Ning LIAO dechang jia Zhihua YANG Yu ZHOU Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of Technology Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Ministry of Industry and Information Technology

Bulk Si_2 BC_3 N ceramics were reinforced with SiC coated multi-walled carbon nanotubes(MWCNTs). The phase compositions, mechanical properties, and thermal shock resistance, as well as the oxidation resistance of the designed Si_2 BC_3 N ceramics were comparatively investigated. The results show that nano SiC coating can be formed on MWCNTs through pyrolyzing polysilazane, which improves the oxidation resistance of MWCNTs. A stronger chemical bonding is formed between the SiC coated MWCNTs and SiC particles, contributing to improved flexural strength(532.1 MPa) and fracture toughness(6.66 MPa m1/2). Besides, the 2 vol% SiC coated MWCNTs reinforced Si_2 BC_3 N ceramics maintains much higher residual strength(193.0 MPa) after thermal shock test at 1000 ℃.The enhanced properties should be attributed to:(1) the breaking of MWCNTs and the debonding between MWCNTs and SiC interfaces, which leads to more energy dissipation;(2) the rough surfaces of SiC coated MWCNTs increase the adhesion strength during the "pull out" of MWCNTs.

关键词： Si2BC3N ceramics SiC coated MWCNTs mechanical properties thermal shock resistance

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Electrochemical properties of La_(0.8)Sr_(0.2)FeO_(3-δ) based composite cathode for intermediate temperature SOFC

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Rare Metals 2006年第Z1期25卷 390-392页

作者： ZHANG Naiqing SUN Kening jia dechang ZHOU Derui The Research Station on Material Science and Engineering for Postoral Fellows Harbin Institute of Technology Harbin 150001 China Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China The Research Station on Material Science and Engineering for Postoral Fellows Harbin Institute of Technology Harbin 150001 China Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China

La0.8Sr0.2FeO3-δ is a new kind of cathode material for intermediate SOFC, but its electrochemical activity is relative poor for the lanthanum gallate based solid oxide fuel cell. In this paper, a novel composite cathode of La0.8Sr0.2FeO3-δ/La0.9Sr0.1Ga0.8Mg0.2O3-δ was prepared on the LSGM electrolyte substrate by screen-printing method. The results of cathodic polarization measurements show that the overpotential decreases significantly when the composite cathode is used instead of the La0.8Sr0.2FeO3-δ single layer cathode. The cathodic overpotential of the composite La0.8Sr0.2FeO3-δ/La0.9Sr0.1Ga0.8Mg0.2O3-δ cathode is 150 mV at the current density of 0.2 A·cm-2 at 800 ℃, while the cathodic overpotential of the La0.8Sr0.2FeO3-δ single layer cathode is higher than 260 mV at the same condition. The electrochemical impedance spectroscopy was employed to investigate the polarization resistance of the cathode. The polarization resistance of the composite cathode is 1.20 Ω·cm2 in open circuit condition, while the value of the single La0.8Sr0.2FeO3-δ cathode is 1.235 Ω·cm2.

关键词： solid oxide fuel cell lanthanum gallate La0.8Sr0.2FeO3-δ composite cathode

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Unveiling structural features and mechanical properties of amorphous Si_(2)BC_(3)N by density functional theory

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Journal of Materials Science & Technology 2023年第8期139卷 103-112页

作者： Yuchen Liu Yu Zhou dechang jia Zhihua Yang Daxin Li Bin Liu Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Zhejiang Laboratory Hangzhou 311100China

The atomic structural features and the mechanical properties of the Si_(2)BC_(3)N are investigated employ-ing ab-initio *** chemical bonding types and their proportion are *** tetrahedral and trigonal configurations,together with their nesting,are identified,which contribute to the flexibil-ity of structural *** Si-related coordination aggravates the inhomogeneous distribution of chemical bonding and weakens the tetrahedral *** accompanying polyhedral distortion is quanti-tatively reflected by the bond length and its deviation of polyhedron *** elastic moduli and the ideal strengths of Si_(2)BC_(3)N are found to be lower than SiC and Si_(3)N_(4),as a result of the weakening effect of coordination Si on tetrahedral units and the existence of easily distorted *** balance between tetrahedral and trigonal features through composition tailor is believed an effective way for the design of Si-B-C-N ceramics for structural applications.

关键词： Amorphous SiBCN Ab-initio calculations Atomic structure Electronic structure Mechanical properties

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Progress of a novel non-oxide Si-B-C-N ceramic and its matrix composites

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Journal of Advanced Ceramics 2012年第3期1卷 157-178页

作者： Pengfei ZHANG dechang jia Zhihua YANG Xiaoming DUAN Yu ZHOU Institute for Advanced Ceramics Harbin Institute of TechnologyHarbin 150080China

In the past twenty years,Si-B-C-N ceramic has attracted wide attention due to its special structure and outstanding *** ceramic generally has an amorphous or a nano-crystalline structure,and has excellent structural stability,oxidation resistance,creep resistance and high-temperature mechanical properties,***,Si-B-C-N ceramic attracts many researchers and finds potential applications in transportation,aerocraft,energy,information,microelectronics and environment,*** work has been carried out on its raw materials,preparation processes,structural evolution,phase equilibrium and high-temperature *** recent years,many researchers focus on its new preparation methods,the preparation of dense ceramic sample with large dimensions,ceramic matrix composites reinforced by carbon fiber or SiC whisker,or components with various *** on Si-B-C-N ceramic will develop our insight into the relationship between structures and properties of ceramics,and will be helpful to the development of novel high-performance *** paper reviews the preparation processes,general microstructures,mechanical,chemical,electrical and optical properties,and potential applications of Si-B-C-N ceramic,as well as its matrix composites.

关键词： Si-B-C-N ceramic preparation method microstructure property

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Direct ink writing of continuous SiO2 fiber reinforced wave-transparent ceramics

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Journal of Advanced Ceramics 2020年第4期9卷 403-412页

作者： Zhe Zhao Guoxiang Zhou Zhihua Yang Xianqi Cao dechang jia Yu Zhou Key Laboratory of Advanced Structural-Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin150001China Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin150080China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China Institute of Petrochemistry Heilongjiang Academy of Science Harbin150001China

This article reports the first example of 3D printed continuous SiO2 fiber reinforced wave-transparent ceramic composites via an adaptation of direct ink writing technology to improve the mechanical and dielectric properties of *** ceramic inks showed good printability by adding nano-SiO2 *** effective continuous fiber-reinforced printing progress was achieved through the design and optimization of the coaxial needle structures by finite element *** printing,the continuous fibers were evenly and continuously distributed in the matrix ceramics and the high molding precision for fiber reinforced composite was *** is demonstrated that 10 vol%continuous SiO2 fiber improved the bending strength of ceramics by about 27%better than that of the ceramics without fiber and the dielectric performance has also been greatly *** novel method unravels the potential of direct ink writing of continuous fiber reinforced wave-transparent ceramics with complex structures and improved properties.

关键词： 3D printing continuous fiber reinforced rheology dielectric properties

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Enhanced thermal shock and oxidation resistance of Si_2BC_3N ceramics through MWCNTs incorporation

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Journal of Advanced Ceramics 2018年第3期7卷 276-288页

作者： Ning LIAO dechang jia Zhihua YANG Yu ZHOU Yawei LI Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of Technology Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Ministry of Industry and Information Technology State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology National–provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology

Multi-walled carbon nanotubes(MWCNTs)reinforced Si_2BC_3N ceramics were prepared through mechanical alloying(MA)and following spark plasma sintering(SPS).The thermal shock resistance of Si_2BC_3N ceramics was evaluated comparatively through ice water quenching test and theoretical ***,the oxidation resistance of MWCNTs incorporated Si_2BC_3N ceramics was evaluated under high *** results show that the calculated parameters such as the critical thermal shock temperature(R)and the thermal stresses resistance(R_(st)),as well as the toughness(R"")are improved with addition of 1 vol%*** addition,the crack propagation resistance of 1 vol%MWCNTs incorporated Si_2BC_3N ceramics is obviously improved through generating more tortuous crack propagation paths attributing to the"crack bridging","pull-out",and"crack deflection"mechanisms of ***,the residual strengths of 1 vol%MWCNTs containing specimens remained the highest after the thermal shock ***,the present work also reveals that the oxidation resistance is more sensitive to relative density than MWCNTs addition.

关键词： Si2BC3N ceramics MWCNTs thermal shock resistance oxidation resistance

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Microstructure and mechanical properties of SiC_(f)/SiBCN ceramic matrix composites

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Journal of Advanced Ceramics 2015年第1期4卷 31-38页

作者： jiaying WANG Zhihua YANG Xiaoming DUAN dechang jia Yu ZHOU Institute for Advanced Ceramics Harbin Institute of TechnologyHarbin 150080Chin

SiC fiber reinforced SiBCN ceramic matrix composites(CMCs)have been prepared by mechanical alloying and consolidated by hot *** the sintering process,amorphous SiC fibers crystallized seriously and transformed ***,the interfacial carbothermal reactions caused the strong bonding between the matrix and *** a result,SiCf/SiBCN fractured in a typical catastrophic ***-temperature mechanical properties reached the maximums for the CMC samples sintered at 1900℃/60 MPa/30 *** density,flexural strength,Young’s modulus and fracture toughness are 2.56±0.02 g/cm^(3),284.3±17.9 MPa,183.5±11.1 GPa and 2.78±0.14 MPa·m^(1/2),respectively.

关键词： hot pressing composites mechanical properties fiber

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Advanced lanthanide doped upconversion nanomaterials for lasing emission

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Journal of Rare Earths 2022年第5期40卷 687-695,I0001页

作者： Yunfei Shang Tong Chen Tianhui Ma Shuwei Hao Weiqiang Lv dechang jia Chunhui Yang School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China College of Materials and Chemical Engineering Heilongjiang Institute of TechnologyHarbin 150050China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150001China Yangtze Delta Region Institute(Huzhou)&School of Physics University of Electronic Science and Technology of ChinaHuzhou 313001China

Microlasers are narrow-band and coherent light from small cavities,which have been widely applied in biomedicine,optical interconnection,integration devices,*** doped upconversion materials are potential gain media for microlasers from near infrared(NIR)to visible and UV regimes due to their multi ladder-like metastable energy levels and superior optical frequency conversion *** optical feedback from photon scattering of the porous upconversion nanoparticles clusters has been reported to produce upconversion random *** light bouncing back and forth between two reflective surfaces or internal surface has been utilized to achieve modulated upconversion lasing *** addition,photon lattices and plasmonic cavities with enhanced electromagnetic fields can amplify the upconversion process within the sub-diffraction volumes and produce highly efficient upconverting *** this review,the recent advances on using lanthanide doped upconversion materials for random,whispering gallery mode(WGM)/Fabry-Perot(FP)cavity and photon lattice/plasmonic cavity modulated upconversion microlasers are *** challenges and future directions of the upconverting lasers are also discussed.

关键词： Lanthanide Upconversion Microlaser Microcavity Rare earths

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Simple and scalable synthesis of super-repellent multilayer nanocomposite coating on Mg alloy with mechanochemical robustness,high-temperature endurance and electric protection

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Journal of Magnesium and Alloys 2022年第9期10卷 2446-2459页

作者： Shuqi Wang Yaming Wang Junchen Chen Yongchun Zou jiahu Ouyang dechang jia Yu Zhou Institute for Advanced Ceramics Harbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China Center of Analysis and Measurement Harbin Institute of TechnologyHarbin 150001China School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China

Multi-functionalization is the future development direction for protective coatings on metal surface,but has not yet been explored a *** effective integration of multiple functions into one material remains a huge ***,a superhydrophobic multilayer coating integrated with multidimensional organic-inorganic components is designed on magnesium alloy via one-step plasma-induced thermal field assisted crosslinking deposition(PTCD)processing followed by after-thermal *** porous MgO ceramic layer and polytetrafluoroethylene(PTFE)nano-particles work as the bottom layer skeleton and filler components separately,forming an organic-inorganic multilayer structure,in which organic nano-particles can be crosslinked and cured to form a compact polymer-like outer layer with hierarchical surface ***,the chemical robustness after prolonged exposure to aqua regia,strong base and simulated seawater solution profits from polymer-like nanocomposite layer uniformly and compactly across the film ***,the self-similar multilayer structure coating endows it attractive functions of strong mechanical robustness(>100th cyclic rotary abrasion),stable and ultra-low friction coefficient(about 0.084),high-temperature endurance,and robust *** organic-inorganic multilayer coating also exhibits high insulating property with breakdown voltage of 1351.8±42.4 V,dielectric strength of 21.4±0.7 V/μm and resistivity of 3.2×10^(10)Ω·*** excellent multifunction benefits from ceramic bottom skeleton,the assembly and deposition of multidimensional nano-particles,and the synergistic effect of organic inorganic *** study paves the way for designing next generation protective coating on magnesium alloy with great potential for multifunctional applications.

关键词： Magnesium alloy Multifunctional multilayer coating Mechanochemical robustness Robust wettability High-temperature endurance

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