Microwave absorption of Co & Zr doped Ba-Sr ferrite at X-Band Ferrite microwave absorbers

Microwave absorption of M-type Ba-Sr hexagonal ferrite has been investigated as a function of substitution of Co-Zr ions at X-band. All the compositions exhibit maximum microwave absorption in the low frequency region (9 GHz). The composition x = 0.8 shows highest reflection loss of -13.91 dB which corresponds to an absorption of 96% at the matching frequency and thickness of 9 GHz and 3.5 mm respectively, making it suitable for microwave absorber application. Composition x = 0.2, with 99% transmitted power at 10.6 GHz, can be used for high frequency lossless applications. Composition x = 1.0 owes 97% reflected power at 8.4 GHz and can be useful for electromagnetic shielding applications. The static or DC current voltage characteristics reveal that all the compositions show ohmic behavior at lower applied field (0-3 volts) and follows exponential trend from 3 to 4.8 volts, except the composition with x = 0.2 which shows voltage independent behavior. The snapshots of the incident signal and the signal transmitted through the ferrite compositions at different frequencies reveal that they only change the amplitude of the signal, while frequency and phase remain unaltered.