Microwave absorption characteristics of chiral materials with Fe3O4-polyaniline composite matrix

• Published in: International journal of electronics 2000-06, Vol.87 (6), p.735-740
• Main Authors: Sun, G. C., Yao, K. L., Liao, H. X., Niu, Z. C., Liu, Z. L.
• Format: Article
• Language: English
• ISSN: 0020-7217; 1362-3060
• DOI: 10.1080/002072100131922

Fe 3 O 4 -polyaniline composites have been prepared in which the concentrations of Fe 3 O 4 are 10%, 15%, 20%, 30% and 40% by weight. Microwave chiral composites are then prepared employing copper helices as chiral inclusions and the Fe 3 O 4 -polyaniline composites as the matrix. The electromagnetic parameters of the chiral Fe 3 O 4 -polyaniline composites are measured using a circular waveguide method at 9.5 GHz, and the normal reflectance from a perfect conductor-backed chiral slab is calculated. The microwave absorption characteristics of the chiral Fe 3 O 4 - polyaniline composites are studied and compared with those of a non-chiral Fe 3 O 4 -polyaniline composite matrix. The results show that the addition of the chiral inclusions to the non-chiral matrix improves both the dielectric and the magnetic losses. As well as this improvement in losses, the chiral materials have higher microwave absorption. The optimal concentration of Fe 3 O 4 in the matrix is about 15% to obtain the lowest reflectance of chiral Fe 3 O 4 -polyaniline composites.