Magnetic resonance behavior modulation of Ba3 Co1.6-x Znx Cu0.4 Fe24 O41 hexaferrites for microwave absorption and surface wave suppression

The intrinsic high magnetocrystalline anisotropy equivalent field can help the hexaferrites break through Snoek's limit and increase the resonance frequency. This is advantageous for microwave absorption applications in the mid to low-frequency range of gigahertz. In this study, we prepared Z -type Ba3 Co1.6-x Znx Cu0.4 Fe24 O41 hexaferrites using the sol-gel auto-combustion method. By changing the ratio of Co and Zn ions, the magnetocrystalline anisotropy of ferrite is further manipulated, resulting in significant changes in their magnetic resonance frequency and intensity. Ba3 Zn1.6 Cu0.4 Fe24 O41 with high-frequency resonance achieved the lowest reflectivity of -72.18 dB at 15.56 GHz, while Ba3 Co1.5 Zn0.1 Cu0.4 Fe24 O41 with stronger loss obtained the widest bandwidth of 4.93 GHz (6.14-11.07). Additionally, we investigated surface wave suppression properties previously overlooked. Ba3 Co1.5 Zn0.1 Cu0.4 Fe24 O41 can achieve a larger attenuation at low frequency under low thickness, which has an excellent effect on reducing backscattering. This work provides a useful reference for the preparation and application of high-performance magnetic-loss materials. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.