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论文类型：期刊论文

发表时间：2020-02-07

发表刊物：JOURNAL OF MATERIALS CHEMISTRY C

收录刊物：EI、SCIE

卷号：8

期号：5

页面范围：1583-1590

ISSN号：2050-7526

摘要：Magnetic microwave absorbing materials (MMAMs) possess many desirable properties, including thin thickness and wide attenuation band, and thus are widely applied in many fields. However, the mechanisms of variation in performance of MMAMs at dynamic temperature are difficult to characterize and poorly understood. In this work, we combine experiments and fluctuation-induced tunneling (FIT) simulations to delineate the effects of temperature on the microwave absorption properties of MMAMs. We find that the increase in temperature weakens the complex permeability of the carbonyl iron particles (CIPs)/epoxy coating, while also strengthening the complex permittivity. FIT simulations explain the experimental observations by showing that the tunneling current between two CIPs with a gap of a few nanometers increases with increasing temperature. Furthermore, crescendo conductance loss and decrescendo magnetic loss form an electric-magnetic complementary effect, so that the coating exhibits superior microwave absorption performance (maximum effective bandwidth 8 GHz) in the temperature range of 293 K-573 K, a result with implications for the broad understanding and design of MMAMs applied at high temperatures.