Article
Chemistry, Physical
Yue Yuan, Shicheng Wei, Yi Liang, Bo Wang, Yujiang Wang, Wei Xin, Xinlei Wang, Yu Zhang
Summary: The cobalt ferrite/carbon nanotubes nanocomposite absorber materials synthesized by a solvothermal method demonstrate excellent absorption properties and a wide absorption bandwidth, making them suitable for microwave absorbers in various technological applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Multidisciplinary Sciences
Nurshahiera Rosdi, Raba'ah Syahidah Azis, Ismayadi Ismail, Nurhidayaty Mokhtar, Muhammad Misbah Muhammad Zulkimi, Muhammad Syazwan Mustaffa
Summary: The study demonstrates that the hybrid of spiraled multiwalled carbon nanotubes and barium hexaferrite nanoparticles exhibits excellent microwave absorption properties, making it a promising microwave absorber for applications in X and Ku bands.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Ceramics
Peng Jiang, Qiang Xu, Ngo Tran, A. S. El-Shafay, V Mohanavel, Anas Abdelrahman, M. Ravichandran
Summary: The microwave performance of CoFe2O4 samples with flower-like and crochet ball-like morphologies (M1 and M2) was studied. By improving the natural resonance frequency and introducing dielectric loss, M1 and M2 samples achieved good reflection loss and ultra-wide effective absorption bandwidth. Furthermore, the special morphologies of M1 and M2 resolved the high-density issue of CoFe2O4.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Fan Qiu, Zhanyong Wang, Min Liu, Zemin Wang, Song Ding
Summary: MXene/NiFe2O4 nanocomposites were successfully prepared via one-step hydrothermal method, showing improved magnetic and electromagnetic properties with the introduction of MXene. The microwave absorption performance was enhanced with the addition of MXene nanosheets.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Yue-Yi Wang, Song-Yang, Wen-Jin Sun, Kun Dai, Ding-Xiang Yan, Zhong-Ming Li
Summary: Barium ferrite (BaFe12O19) is a potential microwave absorption material, but the performance is limited by the poor dispersion of carbon nanotubes (CNTs) in the composites prepared by ball-milling method. In this study, CNTs were uniformly introduced into the precursor of BaFe12O19 during the auto-ignition process and calcined under different atmospheres. The resulting CNT/BaFe12O19 composites exhibited significantly improved microwave absorption performance compared to pure BaFe12O19 and CNT/BaFe12O19 composites prepared by ball-milling method.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Xueyu Xiang, Zhihong Yang, Gang Fang, Yu Tang, Yuping Li, Yujing Zhang, Dong-Hyun Kim, Chuyang Liu
Summary: In this review, the characteristics of typical ferrites for microwave absorption and their suitable synthesis techniques are systematically introduced. The various tailoring tactics, including ions doping, magnetic coupling, integration of magnetic and dielectric properties, and structure design, are thoroughly compared. Furthermore, an in-depth investigation on performance enhancement and internal optimization mechanisms of ferrite MAMs is carried out, and the development directions and future prospects for ferrite MAMs are proposed and predicted.
MATERIALS TODAY PHYSICS
(2023)
Article
Engineering, Environmental
Xiaojun Chen, Mingzhe Yang, Xusheng Zhao, Dechao Hu, Wei Liu, Wenshi Ma
Summary: This study utilized cerium ferrite nanoparticles and multi-walled carbon nanotubes to prepare a novel CeFe2O4/MWCNTs microwave absorber nanocomposite, achieving outstanding superhydrophobicity through the addition of polydimethylsiloxane. The nanocomposite exhibited favorable thermal stability, improved impedance matching, and excellent electromagnetic wave absorption performance, with a maximum reflective loss of -47 dB at 11.3 GHz.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Jongheun Lee, Juseop Lee
Summary: This article introduces a systematic approach for designing transmission-line canonical cross-coupled filters. By properly utilizing two types of standard building blocks (N-type and P-type), a filter schematic can be formulated from a coupling diagram with arbitrary sign combination of coupling coefficients. Practical filter schematics and their design formulas are presented. Instructions on how to use the design formulas in actual filter designs are provided. Design and implementation examples of two sixth-order filters are discussed for demonstration.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Materials Science, Ceramics
Jiali Song, Yu Gao, Guoguo Tan, Qikui Man, Zhi Wang
Summary: In this study, spinel Ni-Zn ferrites with excellent microwave absorption properties were synthesized and their absorption characteristics and interaction mechanisms were investigated. The results showed that S-NZFO had a wide effective absorption bandwidth and high saturation magnetization, while H-NZFO had small particle size and high complex permittivity. Both materials demonstrated potential as efficient microwave absorbers in military and civilian applications.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Jun Li, Yang Hong, San He, Weike Li, Han Bai, Yuanhua Xia, Guangai Sun, Zhongxiang Zhou
Summary: The synthesis of titanium-doped barium ferrite ceramics using a modified sol-gel method is investigated. The crystal structure and magnetic structure are determined using neutron diffraction, and the ceramics show high quality single phase and sheet microstructure. The Ti4+ doping leads to double resonance peaks in the imaginary part of magnetic conductivity, allowing for wideband modulation microwave absorption. These ceramics exhibit excellent frequency modulation ability in the microwave absorption field.
JOURNAL OF ADVANCED CERAMICS
(2022)
Article
Materials Science, Ceramics
Muhammad Adnan Aslam, Kang Hu, Wei Ding, Ali Hassan, Yuecheng Bian, Kang Qiu, Qiangchun Liu, Zhigao Sheng
Summary: By changing the dimensionality of bio-carbon materials, the microwave absorption properties of ferrite/carbon composites can be effectively improved, with the minimum reflection loss enhanced from -9 dB to -45 dB. Adjusting the thickness of ZFO/3D-bio-carbon samples allows for a wide absorption range from 4 to 18 GHz, with an effective absorption bandwidth up to 7.1 GHz covering the entire Ku band.
CERAMICS INTERNATIONAL
(2021)
Article
Engineering, Environmental
Kang Zhang, Xin Li, Yulong Li, Junwei Lv, Rui Qin, Xu Wang, Xiangyang Liu, Yang Liu
Summary: This study presents a facile method to improve the microwave absorption properties of ferrites through direct fluorination. The fluorinated Fe3O4 (F-Fe3O4) exhibits a unique 'magnetoelectric collaborative resonance' (MDR) effect, with double dielectric and magnetic resonance peaks at 14.8 and 16.6 GHz. The smaller energy gap derived from fluorine doping facilitates electron hopping and accumulation, inducing magnetic exchange interactions and the Maxwell-Wagner effect. As a result, F-Fe3O4 shows improved microwave absorption properties compared to pristine Fe3O4.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Xiangyu Wang, Xiaowei Lv, Zhengwang Liu, Huibin Zhang, Minmin Liu, Chunyang Xu, Xiaodi Zhou, Mingyue Yuan, Liting Yang, Wenbin You, Limin Wu, Chongyun Liang, Hualiang Lv, Jincang Zhang, Renchao Che
Summary: A novel multi-interfacial one-dimensional magnetic ferrite@C fibers composite was synthesized through a facile electrospinning and annealing process. The as-prepared ferrite@C fibers exhibit excellent EM absorption properties with a minimum reflection loss of -47.42 dB at 13.52 GHz and a super-wide effective absorption bandwidth of 9.28 GHz (8.24-17.52 GHz) at 3.3 mm.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Qihua Liang, Zhaofei Tong, Jinxiang Guo, Man Wang, Qingrong Yao, Huaiying Zhou
Summary: Barium ferrite is a multiferroic material with excellent properties and can easily improve its performance through doping. By replacing Ba ions with Nd ions, the magnetic performance of the material is enhanced, leading to improved microwave absorption characteristics and a wider range of applications. When the doping content reaches 0.10, the material shows optimal performance with maximum saturation magnetization, coercive force, and microwave absorption properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Materials Science, Ceramics
Mu Zhang, Le Chen, Yang Yu, Xianfeng Meng, Jun Xiang
Summary: In this study, carbon nanofiber supported cobalt ferrite composites (C/CFO) were prepared using electrospinning and hydrothermal methods, displaying excellent microwave absorption properties due to their unique 3D network structure, composite composition, and synergistic effect between C NFs and CFO NPs. With 10 wt % of CFO NPs, the C/CFO samples exhibited superior RLmax of -137 dB at 11.36 GHz and EAB (RL < -10 dB) of 11.44 GHz (6.59 GHz-18 GHz), surpassing single component absorbents, showing great potential for military and civilian applications.
CERAMICS INTERNATIONAL
(2021)
Article
Physics, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: The quarter-wavelength model suggests that the reflection of microwaves can be minimized by adjusting the film thickness to m lambda/4, where m is an odd integer and lambda is the wavelength within the film. However, this study challenges the validity of the model and proposes an alternative approach based on wave superposition principles. The study also criticizes the inappropriate use of certain concepts in current mainstream microwave absorption theory, such as the characterization of microwave absorption using reflection loss RL from materials.
Article
Thermodynamics
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: The study of the Gibbs-Duhem equation and its applications is one of the most difficult topics in thermodynamics. This paper presents a novel mathematical derivation that is shown to be more natural, direct, and intuitive than the traditional thermodynamic derivation. By introducing Legendre transformations, multiple perspectives for problem-solving are provided.
INTERNATIONAL JOURNAL OF THERMOPHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: For many years, it has been common practice to use reflection loss defined for devices to characterize materials, which has caused many problems. By replacing the flawed theory of impedance matching with wave superposition theory and using simple geometry to represent film absorption, the real mechanism of film absorption has been revealed. It is shown that film and material are different, and absorption efficiency is influenced by factors such as wave superposition and energy conservation.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: This section discusses the application of impedance matching and quarter-wavelength theories in microwave absorption research, pointing out their flaws and proposing a new theory to replace the quarter-wavelength theory.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: Energy conservation is crucial for understanding the mechanism of microwave absorption by films. In the past, confusion between films and materials has caused many issues. By considering energy conservation, the differences between films and materials are clarified, and some difficult issues have been explained.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Physics, Applied
Ying Liu, Michael G. B. Drew, Yue Liu
Summary: In the previous Part I, it was demonstrated using transmission-line theory that impedance matching theory should be replaced by wave cancellation theory. It was also shown that film is different from the material and phase effects from interfaces should be considered in quarter wavelength theory. In this Part, it is proven that energy penetration in a film cannot be defined and impedance matching is flawed as it lacks theoretical proof and consistency with experimental data. The multiple absorption peaks in a film arise from wave cancellation under the constraint of energy conservation, rather than resonances from the material.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Ying Liu, Michael G. B. Drew, Yue Liu
Summary: This study theoretically confirms that the absorption mechanism in a film, responsible for the minima of the reflection loss (RL/dB), is best explained by wave cancelation theory rather than by impedance matching theory. The study also reveals that the mechanisms for a film and material are different. In addition, the flaws of neglecting the phase effects of interfaces in a film in quarter-wavelength theory are quantitatively discussed.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Condensed Matter
Ying Liu, Xiangbin Yin, Michael G. B. Drew, Yue Liu
Summary: By analyzing experimental data, this study provides new theoretical perspectives on the inadequacies of impedance matching theory in the field of microwave absorption. It suggests that the current theories related to impedance matching need to be replaced by wave cancellation theory, as even different criteria cannot solve the problems with impedance matching. The analysis in this work supports the new theories against the current ones by applying to published data and determining the conditions for the minima of reflection loss at large values of |Zin - Z0| through transmission-line theory.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Ying Liu, Yi Ding, Yue Liu, Michael G. B. Drew
Summary: It is commonly believed that two synergistic effects maximize microwave absorption power of a film - increasing the absorption power of the material and the penetration of incident microwaves into the film. However, this reasoning is incorrect as it confuses material with film and is not consistent with the real absorption mechanism. By differentiating film from material, it is shown that reflection loss (RL) is relevant only for film and the real mechanism involves balancing the intensities of the two beams reflected from the film's interfaces when they are out of phase by π. It is commonly believed incorrectly that maximum absorption from film occurs when the resultant beam reflected back to open space from the metal-back interface is weakest. But it is shown here that the opposite is true - maximum absorption occurs when this reflected beam reaches its maximum. A definition for film in the context of microwave absorption is proposed.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Ying Liu, Yi Ding, Yue Liu, Michael G. B. Drew
Summary: Part 1 of this work demonstrates that film absorption is based on wave cancellation theory (WCT) rather than the mechanism of material attenuation power and impedance matching theory (IM). The film thickness and material properties affect the pattern of the reflection loss curve and the occurrence of multiple absorption peaks. Maximum absorption occurs when the two reflected beams are out of phase by & pi; at the front of the film, regardless of whether the film has a metal back or not. WCT explains the deviations of maximum absorption positions from the predicted values of IM.
SURFACES AND INTERFACES
(2023)
