Multiscale Assembly of Grape-Like Ferroferric Oxide and Carbon Nanotubes: A Smart Absorber Prototype Varying Temperature to Tune Intensities.
Ideal electromagnetic attenuation material should not only shield the electromagnetic interference but also need strong absorption. Lightweight microwave absorber with thermal stability and high efficiency is a highly sought-after goal of researchers. Tuning microwave absorption to meet the harsh requirements of thermal environments has been a great challenge. Here, grape-like Fe3O4-multiwalled carbon nanotubes (MWCNTs) are synthesized, which have unique multiscale-assembled morphology, relatively uniform size, good crystallinity, high magnetization, and favorable superparamagnetism. The Fe3O4-MWCNTs is proven to be a smart microwave-absorber prototype with tunable high intensities in double belts in the temperature range of 323-473 K and X band. Maximum absorption in two absorbing belts can be simultaneously tuned from ∼-10 to ∼-15 dB and from ∼-16 to ∼-25 dB by varying temperature, respectively. The belt for reflection loss ≤-20 dB can almost cover the X band at 323 K. The tunable microwave absorption is attributed to effective impedance matching, benefiting from abundant interfacial polarizations and increased magnetic loss resulting from the grape-like Fe3O4 nanocrystals. Temperature adjusts the impedance matching by changing both the dielectric and magnetic loss. The special assembly of MWCNTs and magnetic loss nanocrystals provides an effective pathway to realize excellent absorbers at elevated temperature.
School of Material Science and Engineering, Beijing Institute of Technology , Beijing, 100081, China.
Ming-Ming
MM
Lu
School of Material Science and Engineering, Beijing Institute of Technology , Beijing, 100081, China.
Mao-Sheng
MS
Cao
School of Material Science and Engineering, Beijing Institute of Technology , Beijing, 100081, China.
Yi-Hua
YH
Chen
School of Science, Minzu University of China , Beijing, 100081, China.
Wen-Qiang
WQ
Cao
School of Material Science and Engineering, Beijing Institute of Technology , Beijing, 100081, China.
Jia
J
Liu
School of Science, Minzu University of China , Beijing, 100081, China.
Hong-Long
HL
Shi
School of Material Science and Engineering, Beijing Institute of Technology , Beijing, 100081, China.
De-Qing
DQ
Zhang
School of Science, Minzu University of China , Beijing, 100081, China.
Wen-Zhong
WZ
Wang
School of Science, Minzu University of China , Beijing, 100081, China.
Jie
J
Yuan
carbon nanotube; magnetic ferroferric oxide; multiscale assembly; smart absorber; temperature dependence