Enhanced microwave absorption performance via surface modification of BaFe12O19.

• Preparation of BaFe 12 O 19 and SmFeO 3 composite by sol–gel method. • Use the henkel diagram, the reciprocal curve of the hysteresis loop and the maximum magnetic energy product to explain the magnetic properties of the BaFe 12 O 19 @SmFeO 3 composite. • The addition of SmFeO 3 moves the microwave absorption frequency of the BaFe 12 O 19 @SmFeO 3 composite to low frequency. • While BaM + SmFeO 3 15% has the best absorbing performance, there are two reflection loss peaks, the maximum reflection loss is −48.5 dB, the bandwidth is 3.4 GHz. In this study, BaFe 12 O 19 (BaM)/SmFeO 3 10%, 15 %, and 20 % were synthesized via the sol–gel method. SmFeO 3 was uniformly attached to the BaM surface in the prepared composite. As the SmFeO 3 content increases, the weak magnetic properties of SmFeO 3 caused a gradual decrease in the saturation magnetization of the composite and a gradual increase in its coercive force. Based on the Henkel diagram, an exchange coupling between the two magnetic phases is observed. Similarly, the high permeability of BaM and the best dielectric properties of SmFeO 3 together improved the microwave absorption performance of the composite. The maximum reflection loss and bandwidth of BaM/15 %SmFeO 3 reached −48.5 dB and 3.4 GHz, respectively. [ABSTRACT FROM AUTHOR]