Barium ferrite(BaFe_(12)O_(19))is considered as potential microwave absorption(MA)material thanks to the large saturation magnetization,high Curie temperature,and excellent chemical stability.The integration of carbon...Barium ferrite(BaFe_(12)O_(19))is considered as potential microwave absorption(MA)material thanks to the large saturation magnetization,high Curie temperature,and excellent chemical stability.The integration of carbon nanotube(CNT)can improve the dielectric loss of BaFe_(12)O_(19)for further enhanced MA perfor-mance,nevertheless,the MA performance is still not desirable because of the poor CNT dispersion in the CNT/BaFe_(12)O_(19)composites,which usually prepared via the ball-milling method,unless high CNT loading was used.Herein,according to the thermal stability of CNT in different atmosphere and the formation mechanism of BaFe_(12)O_(19)from precursor,CNT was introduced in the precursor of BaFe_(12)O_(19)uniformly during auto-ignition process and calcined under different atmosphere.When CNT loading is only 2.0 wt%,the CNT/BaFe_(12)O_(19)composites obtained exhibits a minimum reflection loss(RL_(min))of-43.9 dB and effective bandwidth(with RL<-10 dB)of 3.9 GHz with the thickness of 1.5 mm,which are much supe-rior to-10.2 dB and 2.2 GHz for pure BaFe_(12)O_(19),and-13.6 dB and 2.5 GHz for CNT/BaFe_(12)O_(19)composite prepared by ball-milling method.These results may pave the way to design high-performance BaFe_(12)O_(19)based microwave absorbers.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51721091,51973142,21878194)the The National Key Research and Development Program of China(2018YFB0704200)the funds of the State Key Laboratory of Solidification Processing(Northwestern Polytechnical University)(SKLSP201918)。
文摘Barium ferrite(BaFe_(12)O_(19))is considered as potential microwave absorption(MA)material thanks to the large saturation magnetization,high Curie temperature,and excellent chemical stability.The integration of carbon nanotube(CNT)can improve the dielectric loss of BaFe_(12)O_(19)for further enhanced MA perfor-mance,nevertheless,the MA performance is still not desirable because of the poor CNT dispersion in the CNT/BaFe_(12)O_(19)composites,which usually prepared via the ball-milling method,unless high CNT loading was used.Herein,according to the thermal stability of CNT in different atmosphere and the formation mechanism of BaFe_(12)O_(19)from precursor,CNT was introduced in the precursor of BaFe_(12)O_(19)uniformly during auto-ignition process and calcined under different atmosphere.When CNT loading is only 2.0 wt%,the CNT/BaFe_(12)O_(19)composites obtained exhibits a minimum reflection loss(RL_(min))of-43.9 dB and effective bandwidth(with RL<-10 dB)of 3.9 GHz with the thickness of 1.5 mm,which are much supe-rior to-10.2 dB and 2.2 GHz for pure BaFe_(12)O_(19),and-13.6 dB and 2.5 GHz for CNT/BaFe_(12)O_(19)composite prepared by ball-milling method.These results may pave the way to design high-performance BaFe_(12)O_(19)based microwave absorbers.