Exchange coupled CoFe2O4/CoFe composites for enhanced microwave absorption properties by in-situ hydrothermal reduction. (May 2022)

• Record Type: Journal Article
• Authors: Bi, Jianhui; Lin, Chucheng; Lu, Danwei; Chen, Ao; Meng, Xianfeng
• Is Part Of: Journal of physics and chemistry of solids. Volume 164(2022)
• Publication Date: 2022-05
• Subjects: Exchange coupling effect -- CoFe2O4/CoFe -- Hydrothermal reaction -- Microwave absorption properties; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2022.110624
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Exchange coupling magnetic composites have been proven to help improve the microwave absorption performance of absorbents. However, composite systems reported showed unsatisfactory exchange coupling effect due to poor particle dispersion and interface contact. Herein, exchange-coupled CoFe2 O4 /CoFe composites were prepared by in-situ hydrothermal reduction. The influence of surfactant on the microstructure and properties were studied in detail. The results showed that the CoFe2 O4 /CoFe samples with hexadecyltrimethylammonium bromide (CTAB) as the surfactant had more two-phase interfaces and excellent dispersion, the grain size of CoFe2 O4 and CoFe were 45 nm and 38.4 nm. Close contact interface and small grain size caused suitable exchange coupling effect, which enhanced the microwave absorption performance of CoFe2 O4 /CoFe composites. The CoFe2 O4 /CoFe sample displayed maximum reflection loss ( RL max ) of −54.8 dB at 3.5 mm thickness and effective absorption bandwidth ( EAB ) of 3.16 GHz, revealing promising prospect in the electromagnetic wave absorption field. Highlights: Exchange Coupled CoFe2 O4 /CoFe Composites were synthesized by in-situ hydrothermal reduction technique. The influence of surfactant on the microstructure and properties was systematically discussed. The CoFe2 O4 /CoFe Composites with CTAB as the surfactant exhibited superior exchange coupling effect. The microwave absorption mechanism was concluded.