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Refractory Metamaterial Microwave Absorber with Strong Absorption Insensitive to Temperature
Author(s) -
Li Yukun,
Li Wei,
Wang Yi,
Cao Jie,
Guan Jianguo
Publication year - 2018
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201800691
Subject(s) - materials science , microwave , permittivity , ceramic , absorption (acoustics) , metamaterial , dielectric , composite material , optoelectronics , dielectric loss , atmospheric temperature range , metamaterial absorber , thermodynamics , physics , tunable metamaterials , quantum mechanics
The so far developed microwave absorbers all exhibit dramatically changing absorption with temperature, hindering them from working in a broad temperature range. Here, a refractory metamaterial microwave absorber (rfMMA) with the absorption insensitive to temperature by using refractory ceramics of conductive titanium diboride (TiB 2 ) as unit cells and dielectric alumina (Al 2 O 3 ) as a spacer is designed and experimentally demonstrated. The as‐proposed rfMMA shows strong microwave absorption in a wide temperature range. A definite physical equivalent circuit model that tightly links the structural and constitutive parameters of the rfMMA to its absorption properties is established. It reveals that with a stable configuration of the as‐proposed rfMMA, the little temperature effect on the permittivity of Al 2 O 3 spacer and the big enough conductivity of TiB 2 unit cells ensure an almost constant absorption in a wide temperature range, avoiding the temperature‐sensitive problem of traditional refractory absorbers. Moreover, the excellent chemical stability of TiB 2 and Al 2 O 3 at high temperature further ensures the long‐term service of the as‐fabricated rfMMA, as confirmed by experiments. This work provides a route to achieve refractory microwave absorbers with strong absorption at a wide temperature range, and illustrates a bright prospect of the all‐ceramic metamaterial absorbers in high temperature applications.