Electromagnetic and microwave absorption properties of BaMgxCo1−xTiFe10O19

To improve the impedance matching and then achieve a better microwave absorption performance in electromagnetic absorber, the Mg2+ was added to occupy the sites of Co2+ in hexagonal-type ferrite BaCoTiFe10O19. BaMgxCo1−xTiFe10O19 were synthesized by a simple sol-gel combustion technique and the phase of BaMgxCo1−xTiFe10O19 was confirmed by X-ray diffraction analysis (XRD). The grain size of BaMgxCo1−xTiFe10O19 was in the range of 100-400 nm and crystal particles were refined with the augment of doped Mg2+. Based on the static magnetic measurement, the coercivity (Hc) increased and the saturation magnetization (Ms) decreased as the x increased. Moreover, it was found that BaMg0.4Co0.6TiFe10O19 possessed a maximum reflection loss of −33.7 dB with a matching thickness of 2.0 mm measured by the vector net-analyzer in the frequency of 0.5-18 GHz, which also had a bandwidth below −20 dB ranging from 11.5 GHz to 17.2 GHz. Meanwhile, the permeability of the prepared ferrites could be adjusted and a proper match was provided between dielectric and magnetic properties by controlling the doped content of Mg2+, which would be significant to the application of BaMgxCo1−xTiFe10O19 in the field of the microwave absorbing materials.