Controllable morphology, dielectric, magnetic and reflection loss characteristics of ferrite/wax composites for low-loss applications

Abstract

In this work, composites of M-type Ba(1−x)SrxFe12O19 hexagonal ferrite (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) and paraffin wax have been prepared. Microwave characterization of the prepared composites was performed with a vector network analyzer from 0.13 GHz to 3 GHz. The dependence of Sr2+ ion content on different compositions was determined in terms of grain morphology, dielectric, magnetic, conductivity, and reflection loss (RL) properties. The grain size varied with dopants and rendered a significant effect on material parameters. The dielectric and magnetic loss tangent were reduced with the increase in frequency and content of Sr2+ ions. The AC conductivity followed the trend of gradual increase with frequency and x=1.0 composition attained the lowest value encompassing the frequency spectrum mostly. The observed RL peaks have been narrow in Ba0.8Sr0.2Fe12O19/wax composite and broad in SrFe12O19/wax composite along with the low frequency spectrum. x=0.6 composition has-0.35×10−3 dB reflection loss at 0.15 GHz. All compositions revealed more than 99.77% unattenuated (low-loss) microwave signal, with −0.01 dB bandwidth ≥1.50 GHz, and owe good scope for their application in low-loss microwave devices.