Modified composition of barium ferrite to act as a microwave absorber in X-band frequencies

The magnetic and electromagnetic wave absorbing properties of the Co–Mn–Ti substituted barium ferrites, BaCoxMnxTi2xFe12−4xO4 (0≤x  ≥0.5), prepared by a solid-state technique, were investigated. The grain size uniformity and densification improved with increasing concentration of Co–Mn–Ti, while the permeability increased and the coercivity decreased remarkably. The reflection coefficients (S11,S12)(S11,S12) of the ferrite samples were measured in the X-band frequency range (8–12 GHz) and their absorbing properties were calculated according to transmission line theory. The maximum reflection loss (−14.7 dB) is observed for the x=0.4x=0.4 sample. A ferromagnetic resonance frequency shift has been observed to depend on the Co–Mn–Ti concentration, which is an important phenomenon of barium ferrite for absorbing microwaves at high frequencies. Based on the magnetic and microwave measurements, BaCoxMnxTi2xFe12−4xO4 may be a good potential candidate for electromagnetic compatibility and for other practical applications at high frequencies.