Enhanced Microwave Absorption Properties of Doped M-Type Barium Hexagonal Ferrites in Ka-band Frequencies

The present study reports the microwave absorption characteristics of La3+-Na+ substituted barium hexaferrites with chemical composition: Ba(1−2x)LaxNaxFe10CoTiO19 and Ba(1−2x)LaxNaxFe10Co0.5TiMn0.5O19 (0.00 ≤ x ≤ 0.25) respectively in Ka-band frequencies. The electromagnetic characteristics such as complex permittivity, complex permeability, and microwave absorption properties were studied using Vector Network Analyzer in 26.5–40.0 GHz frequency band. Dielectric properties showed almost constant variation with increase in frequency. Magnetic permeability spectra observed wavy variation with frequency. Comparing the electromagnetic properties of two series, it is observed that Co–Ti–Mn series observes higher values of electromagnetic properties in comparison to Co–Ti series. For composition x = 0.15 of Ba(1−2x)LaxNaxFe10Co0.5TiMn0.5O19 series, −55.33 dB reflection loss at 30 GHz frequency with −10 dB absorption bandwidth around 3.51 GHz has been observed. Thus, these materials can be employed as effective absorbers for Ka-band microwave absorbers.