Transition/rare earth metal co-modified SiC for low-frequency and high-temperature electromagnetic response
Zhanming Wu, Jun Huang, Yunan Tan, Xiaomei Deng, Xiaojun Zeng
Abstract
Low-frequency electromagnetic response in microwave technology exhibits unprecedented demand, benefiting applications such as 5G communications, Wi-Fi, and radar systems. To date, the purest low-frequency response materials are induced by magnetic metals. However, magnetic metals will demagnetize at high temperatures and cannot serve in high-temperature environments. Here, we introduced a SiC/CoSi/CeSi composite co-modified with transition metal Co and rare earth metal Ce, achieving a 14-fold increase in reflection loss (<em>R</em><sub>L</sub>) from -4.74 dB to -66.48 dB. The effective absorption bandwidth (EAB, <em>R</em><sub>L</sub>≤-10 dB) is 2.46 GHz. With the SiC/CoSi/CeSi composite, the effective absorption frequency is shifted to the low-frequency band (3.65 GHz), and the high-temperature stability (500 °C) is maintained, inheriting 94.5% effective absorption. Radar cross-section (RCS) simulation further confirms the excellent stealth capability of the composite, reducing the target reflection intensity by 22.7 dB m<sup>2</sup>. Mechanism investigation indicates that the excellent EMW absorption performance of the composite is attributed to multiple reflections and scattering, conduction losses, abundant interface polarization, and good magnetic loss. This research supplies critical inspiration for developing efficient SiC-based absorbers with both low-frequency and high-temperature responses.