Microwave Ferrites: Synthesis, Characterization, AC-DC & Microwave Absorption Studies of Ba-Sr Hexaferrites at X-Band

Hexagonal ferrites are incorporated in microwave communication technology, recording, anti-electromagnetic interference coatings, radar absorbing materials (RAM), transformers and other technological applications. In this work we have synthesized M-type Ba0.5Sr0.5MxFe(12-2x)O19 (M = Co-Ru, Co-Zr and Co-Ti) and Ba(1-x)SrxFe12O19 hexagonal ferrite and characterized ferrite using XRD and SEM. Hysteresis parameters have been investigated as a function of substitution. Complex permittivity, Complex permeability and Reflection loss have been studied as a function of frequency (X-band), substitution and thickness. Sample 1.0 of Co-Zr ferrite shows maximum absorption with reflection loss of -37 dB at 12.08 GHz, rendering its use for microwave absorber application. High temperature enhances dielectric properties in comparison to the magnetic properties in Ba0.5Sr0.5MxFe(12-2x)O19 and Ba(1-x)SrxFe12O19 ferrite. Saturation magnetization increases in Ba0.5Sr0.5MxFe(12-2x)O19 ferrite at lower substitution whereas it decreases at higher substitution. Remanence magnetization is increases: with Sr ions substitution in Ba(1-x)SrxFe12O19 ferrite and in the undoped sample 0.0 of Ba0.5Sr0.5MxFe(12-2x)