Detailed microwave absorption performance of BaFe12O19 nano-hexaplates with a large variety of thicknesses

We successfully prepared BaFe12O19 (BaM) nano-hexaplates using the co-precipitation method followed by heat treatment. The hexaplate-like grain size varied in the range of 50-200 nm, while its crystalline size was similar to 46 nm. Before investigating microwave absorption, structural and magnetic properties were studied by x-ray diffraction, Raman scattering, and a vibrating sample magnetometer. The structural studies showed a pure phase of BaM, while the magnetic studies revealed a ferro/ferrimagnetic behaviour with M-s = 59.93 emu g(-1), M-r = 32.49 emu g(-1), and H-c = 5.16 kOe. Microwave dissipation features were systemically investigated for device thickness of 0.25-10 mm with a measured frequency range of 2-16 GHz. The study showed that the BaFe12O19 sample could absorb more than 99.9% of the incident microwave in the 12-14 GHz frequency range for 6.5 mm thickness. The effective absorption bandwidth was also fairly large, as similar to 3 GHz in this frequency range. The microwave dissipation features of BaM in this work were better than pure BaM ones in other studies and relatively comparable with BaM-based microwave absorbers. The magnetic loss originated from natural resonance, while the dielectric loss resulted from multi-interface, interface, and dipolar polarization. Overall, the BaFe12O19 sample in this study could be used as a promising microwave absorber in the Ku waveband.