 Ni1x coax at carbon composites were synthesized using a solvothermal method followed by annealing treatment. The resulting material had a unique core shell structure consisting of magnetic particles and carbon shells. This structure allowed for strong magnetic and dielectric properties, which could be used for microwave absorption applications. The absorption performance of these composites was enhanced when the amount of absorbing material increased from 25% to 40% while maintaining a high reflection loss of minus 59.5 dB. Furthermore, the absorption bandwidth was found to increase from 3.8 GHz to 4.7 GHz when the absorbing material was increased from 25% to 40%. These results suggest that the magnetic dielectric synergy effect plays a key role in the absorption performance of these composites. This article was authored by Lei Huang, Mingqiu Huang, Xie Fengyu, and others.