Full XKu band microwave absorption by Fe(Mn)/Mn 7C 3/C core/shell/shell structured nanocapsules
Full XKu band microwave absorption by Fe(Mn)/Mn 7C 3/C core/shell/shell structured nanocapsules
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DOI：
10.1016/j.jallcom.2011.06.031
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发表时间：
2011-09
影响因子：
5.6
通讯作者：
Xianguo Liu;S. Wing;S. Ho;C. C. Cheung-C.;C. Leung;Z. Han;D. Geng;Zhidong Zhang
中科院分区：
文献类型：
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作者：
Xianguo Liu;S. Wing;S. Ho;C. C. Cheung-C.;C. Leung;Z. Han;D. Geng;Zhidong Zhang
采用改进的乙醇蒸气电弧放电技术制备了以Fe(Mn)固溶体纳米粒子为核、Mn7C3为内壳、石墨为外壳的新型Fe(Mn)/Mn7C3/石墨纳米胶囊。由于核/壳/壳界面以及电介质 Mn7C3 和 C 壳的协同作用，采用科尔-科尔半圆方法来解释三元介电共振。各向异性能量的显着增加导致自然共振频率移至 6.6GHz。介电损耗来自三元介电共振，而磁损耗来自磁自然共振。对于 5.0mm 厚度的层，在 12GHz 下观察到最佳反射损耗 (RL) 为 -142.1dB。在 1.4mm 厚度下，在 6.6–18GHz 下获得了超过 -10dB 的 RL，覆盖整个 X 频段（8–12GHz）、Ku 频段（12–18GHz）和部分 C 频段（6.6–8.0GHz）。对于 2.2mm 厚度，在 6–10.6GHz 下发现 RL 超过 -20dB。
New type of Fe(Mn)/Mn7C3/graphite nanocapsules was prepared by a modified arc discharge technique in ethanol vapor, with Fe(Mn) solid solution nanoparticles as the core, Mn7C3as the inner shell, and graphite as the outer shell. The Cole–Cole semicircle approach was adopted to explain the ternary dielectric resonance, due to a cooperative consequence of the core/shell/shell interfaces and the dielectric Mn7C3and C shells. A remarkable increase in the anisotropy energy led to a shift in the natural resonance frequency to 6.6GHz. Dielectric losses come from the ternary dielectric resonance while magnetic losses were from the magnetic natural resonance. An optimal reflection loss (RL) of −142.1dB was observed at 12GHz for 5.0mm thickness layer. RL exceeding −10dB was obtained at 6.6–18GHz for 1.4mm thickness, covering the whole X band (8–12GHz), Ku band (12–18GHz), and some of C band (6.6–8.0GHz). RL exceeding −20dB was found at 6–10.6GHz for 2.2mm thickness.