Abstract
•Three microwave absorbers of Bi2Te3 based on different size (30.7 µm, 43.1 ± 3 nm and 20.1 ± 3 nm) have been designed.•The size of the Bi2Te3 based absorbers has shown a great impact on the microwave absorbing features.•The Bi2Te3 (20.1 ± 3 nm) absorber with thickness 1.51 mm exhibits a minimum reflection loss (RL= ─ 60 dB) at f = 15.47 GHz.
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Innovation of an excellent microwave absorber with a wide effective absorption bandwidth, high conductivity, and easy processability has become a hard dare, which obstructs its prospective applications. Thus, three microwave absorbers of Bi2Te3 based on different size (labelled BT1 ~30.7 µm, BT2 ~43.1 ± 3 nm and BT3 ~20.1 ± 3 nm) have been designed for this purpose, for the first time. BT3 absorbers have shown a surface area (70.9 m2/g) larger than BT2 (41.39 m2/g) and BT1 (2.34 m2/g). The size of the Bi2Te3 based absorbers has shown a great impact on the microwave absorbing features. The smaller size/diameter of Bi2Te3 has displayed a higher EM absorption, whereas the BT3 (20.1 ± 3 nm) absorber with thickness 1.51 mm exhibits a minimum reflection loss (RL= ─ 60 dB) at f = 15.47 GHz while the BT2 (43.1 ± 3 nm) exhibits a (RL = ─ 34.9 dB at 6.59 GHz for 4.1 mm) and (RL= ─25 dB at 7 GHz for 4.1 mm) for BT1 (30.7 µm). Also, the BT3 absorber shows an effective absorption bandwidth (8 GHz at 2.1 mm) extending from 10 to 18 GHz better than the other two shields (7.01 GHz at 2.1 mm) for the BT2 and (6.01 GHz at 2.6 mm) for the BT1. The dielectric loss is the prevailing factor participates in the strong EM absorption mode. The smaller size Bi2Te3 (BT3) absorber has recorded the highest thermal conductivity k = 1.41 W/mK, proving the larger thermal energy storages of these absorber. Finally, these Bi2Te3 particles based EM absorbers may have potential applications as an efficient EM absorption material in broad bandwidth of frequency in electronic, electrical and military devices thanks to their lightweight, small size and smart features.