Effects of Ni-doping on microstructure, magnetic and microwave absorption properties of CoFe2O4

•Nano-spinel powder samples of Co1–xNixFe2O4(x = 0, 0.1, 0.3, 0.5) were successfully synthesized by sol–gel method.•Ni doping changes the ion concentration at the [A][B] position and affects the magnetic properties of CoFe2O4.•Different microwave absorption mechanisms of Co1–xNixFe2O4 (x = 0, 0.1, 0.3, 0.5) samples.•The Co1–xNixFe2O4(x = 0, 0.1, 0.3, 0.5) samples exhibit excellent microwave absorption performance.