Chin. Phys. B, 2022, Vol. 31(11): 114206    DOI: 10.1088/1674-1056/ac81ac
 ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS Prev   Next

# Microwave absorption properties regulation and bandwidth formula of oriented Y2Fe17N3-δ@SiO2/PU composite synthesized by reduction-diffusion method

Hao Wang(王浩)1, Liang Qiao(乔亮)1,†, Zu-Ying Zheng(郑祖应)1, Hong-Bo Hao(郝宏波)2, Tao Wang(王涛)1, Zheng Yang(杨正)1, and Fa-Shen Li(李发伸)1
1 Institute of Applied Magnetism, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China;
2 State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization, Baotou 014000, China
Abstract  As concepts closely related to microwave absorption properties, impedance matching and phase matching were rarely combined with material parameters to regulate properties and explore related mechanisms. In this work, reduction-diffusion method was innovatively applied to synthesize rare earth alloy Y$_{2}$Fe$_{17}$. In order to regulate the electromagnetic parameters of absorbers, the Y$_{2}$Fe$_{17}$N$_{3-\delta }$ particles were coated with silica (Y$_{2}$Fe$_{17}$N$_{3-\delta }$@SiO$_{2}$) and absorbers with different volume fractions were prepared. The relationship between impedance matching, matching thickness, and the strongest reflection loss peak (${\rm RL}_{\rm min}$) was presented obviously. Compared to the microwave absorption properties of Y$_{2}$Fe$_{17}$N$_{3-\delta }$/PU absorber, Y$_{2}$Fe$_{17}$N$_{3-\delta }$@SiO$_{2}$/PU absorbers are more conducive to the realization of microwave absorption material standards which are thin thickness, light weight, strong absorbing intensity, and broad bandwidth. Based on microwave frequency bands, the microwave absorption properties of the absorbers were analyzed and the related parameters were listed. As an important parameter related to perfect matching, reflection factor ($\sqrt {ărepsilon_{\rm r}/\mu_{\rm r}}$) was discussed combined with microwave amplitude attenuation. According to the origin and mathematical model of bandwidth, the formula of EAB (${\rm RL}<-10$ dB) was derived and simplified. The calculated bandwidths agreed well with experimental results.
Keywords:  microwave absorption      rare earth alloy      reduction-diffusion method      Y2Fe17N3-δ@SiO2      reflection factor      impedance and phase matching      bandwidth formula
Received:  23 May 2022      Revised:  14 July 2022      Accepted manuscript online:  18 July 2022
 PACS: 42.25.Bs (Wave propagation, transmission and absorption) 75.50.Bb (Fe and its alloys) 76.30.Kg (Rare-earth ions and impurities) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))
Fund: Project supported by the National Key Research and Development Program of China (Grant No. 2021YFB3501300), the National Natural Science Foundation of China (Grant No. 51731001), and the Fund from the State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization’s Key Research and Development Projects.
Corresponding Authors:  Liang Qiao     E-mail:  qiaoliang@lzu.edu.cn