Fabrication of RADAR Absorbing composite Materials For Defense Applications

Abstract

In this dissertation work the electromagnetic absorption properties of Bar ium ferrite based composites are studied in the 0-18GHz frequency range as Barium ferrite (BaFe12O19) is regarded as a promising microwave absorp tion (MA) material owing to its superior magnetic properties like saturation magnetization, Curie temperature, and excellent chemical stability.in this dissertation ,doped barium ferrites were prepared and the effect of doping was studied.the results showed that the substitution ofSr+2 effectively im proved the absorption.further doping of carbonyl Iron(CI) and MWCNTs only enhanced the dielectric and magnetic properties of the material because of the integration of the dielectric properties of MWCNT and the magnetic properties of CI.it is noted that at a matching thickness of 5mm ,maximum reflection loss of-29dB is achieved.the structure and morphology of the sam ples were investigated using XRD and FESEM which revealed the hexagonal structure of the samples.VNA was used to study the dielectric and magnetic properties of the sample.the hysteresis loop was studied using the vibrating sample magnetometer.