Enhanced microwave absorption performance via surface modification of BaFe12O19

•Preparation of BaFe12O19 and SmFeO3 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 BaFe12O19@SmFeO3 composite.•The addition of SmFeO3 moves the microwave absorption frequency of the BaFe12O19@SmFeO3 composite to low frequency.•While BaM + SmFeO315% 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.