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

Abstract

Abstract Fe3O4-polyaniline composites have been prepared in which the concentrations of Fe3O4 are 10%, 15%, 20%, 30% and 40% by weight. Microwave chiral composites are then prepared employing copper helices as chiral inclusions and the Fe3O4-polyaniline composites as the matrix. The electromagnetic parameters of the chiral Fe3O4-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 Fe3O4- polyaniline composites are studied and compared with those of a non-chiral Fe3O4-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 Fe3O4 in the matrix is about 15% to obtain the lowest reflectance of chiral Fe3O4-polyaniline composites.