Microwave absorbing materials using Ag-NiZn ferrite core-shell nanopowders as fillers
Microwave absorbing materials using Ag-NiZn ferrite core-shell nanopowders as fillers
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DOI：
10.1016/j.jmmm.2004.06.026
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发表时间：
2004-12-01
影响因子：
2.7
通讯作者：
Chen, SY
中科院分区：
文献类型：
--
作者：
Peng, CH;Wang, HW;Chen, SY
采用水热法合成了不同铁氧体/银比（铁氧体/银=6/1、4/1、2/1、1/1、1/6）的Ni0.5Zn0.5Fe2O4尖晶石铁氧体包覆的核壳结构银纳米粒子，并将其引入聚氨酯基体中作为微波吸收剂。在2-15 GHz频率范围内测量了铁氧体/银核壳纳米粉体和聚氨酯复合吸波材料的复介电常数（epsilon'、epsilon"）和磁导率（mu'、mu"）。使用不同铁氧体/银比率的吸收壁理论，根据测量数据计算反射损耗和匹配频率。结果发现，当使用 NiZn 铁氧体作为填料时，随着核壳纳米填料的铁氧体/银比率从 6/1 降至 2/1，反射损耗的匹配频率在 9.0 GHz 时超过了令人满意的 -25dB，并转移到更高的频率（10.9-13.7 GHz）。目前的结果表明，通过控制复合材料中核壳纳米填料的铁氧体/银比例，可以制造出适用于 9 GHz 以上应用的使用铁氧体/银核壳填料的微波吸收体，特定频率的反射损耗超过 -25 dB。 (C) 2004 Elsevier B.V. 保留所有权利。
Silver nanoparticles coated with Ni0.5Zn0.5Fe2O4 spinel ferrites, forming a core-shell structure, were synthesized by utilizing hydrothermal method at different ferrite/silver ratio (ferrite/silver = 6/1, 4/1, 2/1, 1/1, 1/6) and introduced into polyurethane matrix to be a microwave absorber. The complex permittivity (epsilon', epsilon") and permeability (mu', mu") of absorbing composite materials consisted of ferrite/silver core-shell nanopowders and polyurethane were measured in the frequency range of 2-15 GHz. The reflection loss and matching frequency were calculated from measured data using theory of the absorbing wall for different ferrite/silver ratios. It was found that the matching frequency for reflection loss exceeded a satisfactory -25dB at 9.0 GHz for using NiZn ferrite as a filler shifts to higher frequencies (10.9-13.7 GHz) as the ferrite/silver ratio of core-shell nano-filler decreased from 6/1 to 2/1. The present result demonstrates that microwave absorbers using ferrite/silver core-shell filler can be fabricated for the applications over 9 GHz, with reflection loss more than-25 dB for specific frequencies, by controlling the ferrite/silver ratio of the core-shell nano-fillers in the composites. (C) 2004 Elsevier B.V. All rights reserved.