Atomic Valence Reversal-Induced Polarization Resonance Spurs Highly Efficient Electromagnetic Wave Absorption in α-Fe<sub>2</sub>O<sub>3</sub>@Carbon Microtubes
Hengdong Ren, Tongshuai Zhu, Lei Feng, Qifan Wu, Ka Wang, Xinjie Yun, Haogang Zhu, Jian Chen, Baojun Wei, Hao Ni, Xiaobing Xu, Zhiyong Zhang, Xinglong Wu
Abstract
Variegation and complexity of polarization relaxation loss in many heterostructured materials provide available mechanisms to seek a strong electromagnetic wave (EMW) absorption performance. Here we construct a unique heterostructured compound that bonds α-Fe 2 O 3 nanosheets of the (110) plane on carbon microtubes (CMTs). Through effective alignment between the Fermi energy level of CMTs and the conduction band position of α-Fe 2 O 3 nanosheets at the interface, we attain substantial polarization relaxation loss via novel atomic valence reversal between Fe(III) ↔ Fe(III – ) induced with periodic electron injection from conductive CMTs under EMW irradiation to give α-Fe 2 O 3 nanosheets. Such heterostructured materials possess currently reported minimum reflection loss of −84.01 dB centered at 10.99 GHz at a thickness of 3.19 mm and an effective absorption bandwidth (reflection loss ≤ −10 dB) of 7.17 GHz (10.83–18 GHz) at 2.65 mm. This work provides an effective strategy for designing strong EMW absorbers by combining highly efficient electron injection and atomic valence reversal.