Single-layer & double-layer microwave absorbers based on Co–Ti substituted barium hexaferrites for application in X and Ku-band

To develop microwave absorbing materials over X and Ku-band, M-type hexaferrites: BaCoxTixFe(12−2 x)O19, with x varying from 0.0 to 1.0 in step size of 0.2, were prepared by solid state reaction route. Characterization techniques like x-ray diffraction, scanning electron micrograph and vibration sample magnetometer were used to analyze the crystalline phases, morphologies, and magnetic properties of the samples. Vector network analyzer was utilized to scrutinize the electromagnetic properties like complex permittivity, complex permeability, and microwave absorption. Results indicate the enhancement of imaginary permittivity and permeability with substitution. Absorption analysis concludes that the composition with x = 0.8 is the best single-layer microwave absorber out of all the prepared compositions with minimum reflection loss −33 dB at thickness of 3.1 mm. At the same time, the compositions x = 0.2, 0.4, 0.6, and 1.0 are combined to form double-layer absorber with absorption more than 99% in X and Ku-band.