Effect of Particle Size and Concentration on Microwave‐Absorbing Properties of Cu x Co 2− x Y ( x =0, 1) Hexaferrite Composites

Co 2 Y‐type hexaferrites (Ba 2 Cu x Co 2− x Fe 12 O 22 , x =0,1) have been fabricated by the conventional ceramic process. The complex permittivity and permeability of Co 2 Y hexaferrite composites have been measured using a vector network analyzer in the frequency range of 2–18 GHz. The results show that Co 2 Y hexaferrite composites have a high permeability and a low permittivity. This can be adjusted by a CuO additive and particle sizes. The reflection loss (RL) values of Co 2 Y hexaferrite composites backed with a conducting plate indicate that the composites possess good microwave‐absorbing properties. The minimum RL value of the composites was below −30 dB. The microwave‐absorbing materials with 10 GHz (8 GHz) bandwidth for attenuation of 5 dB (10 dB) can be achieved.