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Dolmatov AV, Maklakov SS, Artemova AV, Petrov DA, Shiryaev AO, Lagarkov AN. Deposition of Thick SiO 2 Coatings to Carbonyl Iron Microparticles for Thermal Stability and Microwave Performance. SENSORS (BASEL, SWITZERLAND) 2023; 23:1727. [PMID: 36772763 PMCID: PMC9919206 DOI: 10.3390/s23031727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/23/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Thick dielectric SiO2 shells on the surface of iron particles enhance the thermal and electrodynamic parameters of the iron. A technique to deposit thick, 500-nm, SiO2 shell to the surface of carbonyl iron (CI) particles was developed. The method consists of repeated deposition of SiO2 particles with air drying between iterations. This method allows to obtain thick dielectric shells up to 475 nm on individual CI particles. The paper shows that a thick SiO2 protective layer reduces the permittivity of the 'Fe-SiO2-paraffin' composite in accordance with the Maxwell Garnett medium theory. The protective shell increases the thermal stability of iron, when heated in air, by shifting the transition temperature to the higher oxide. The particle size, the thickness of the SiO2 shells, and the elemental analysis of the samples were studied using a scanning electron microscope. A coaxial waveguide and the Nicholson-Ross technique were used to measure microwave permeability and permittivity of the samples. A vibrating-sample magnetometer (VSM) was used to measure the magnetostatic data. A synchronous thermal analysis was applied to measure the thermal stability of the coated iron particles. The developed samples can be applied for electromagnetic compatibility problems, as well as the active material for various types of sensors.
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Artemova AV, Maklakov SS, Osipov AV, Petrov DA, Shiryaev AO, Rozanov KN, Lagarkov AN. The Size Dependence of Microwave Permeability of Hollow Iron Particles. SENSORS 2022; 22:s22083086. [PMID: 35459071 PMCID: PMC9029975 DOI: 10.3390/s22083086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 02/01/2023]
Abstract
Hollow ferromagnetic powders of iron were obtained by means of ultrasonic spray pyrolysis. A variation in the conditions of the synthesis allows for the adjustment of the mean size of the hollow iron particles. Iron powders were obtained by this technique, starting from the aqueous solution of iron nitrate of two different concentrations: 10 and 20 wt.%. This was followed by a reduction in hydrogen. An increase in the concentration of the solution increased the mean particle size from 0.6 to 1.0 microns and widened particle size distribution, but still produced hollow particles. Larger particles appeared problematic for the reduction, although admixture of iron oxides did not decrease the microwave permeability of the material. The paraffin wax-based composites filled with obtained powders demonstrated broadband magnetic loss with a complex structure for lesser particles, and single-peak absorption for particles of 1 micron. Potential applications are 5G technology, electromagnetic compatibility designs, and magnetic field sensing.
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Cao F, Xu J, Zhang X, Li B, Zhang X, Ouyang Q, Zhang X, Chen Y. Tuning Dielectric Loss of SiO 2@CNTs for Electromagnetic Wave Absorption. NANOMATERIALS 2021; 11:nano11102636. [PMID: 34685081 PMCID: PMC8537562 DOI: 10.3390/nano11102636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/01/2021] [Accepted: 10/03/2021] [Indexed: 11/16/2022]
Abstract
We developed a simple method to fabricate SiO2-sphere-supported N-doped CNTs (NCNTs) for electromagnetic wave (EMW) absorption. EMW absorption was tuned by adsorption of the organic agent on the precursor of the catalysts. The experimental results show that the conductivity loss and polarization loss of the sample are improved. Meanwhile, the impedance matching characteristics can also be adjusted. When the matching thickness was only 1.5 mm, the optimal 3D structure shows excellent EMW absorption performance, which is better than most magnetic carbon matrix composites. Our current approach opens up an effective way to develop low-cost, high-performance EMW absorbers.
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Affiliation(s)
- Fenghui Cao
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
- School of Mechatronic Engineering, Daqing Normal University, Daqing 163712, China
| | - Jia Xu
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
| | - Xinci Zhang
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
| | - Bei Li
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
| | - Xiao Zhang
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
- Correspondence: (X.Z.); (Y.C.)
| | - Qiuyun Ouyang
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
| | - Xitian Zhang
- Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, China;
| | - Yujin Chen
- Key Laboratory of In-Fiber Integrated Optics, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China; (F.C.); (J.X.); (X.Z.); (B.L.); (Q.O.)
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (X.Z.); (Y.C.)
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