Ferromagnetic metal/alloy particles can effectively regulate the electromagnetic properties,but the eddy current effect induced by the local agglomeration of particles limits the further improvement of the material′s electromagnetic absorbing properties.In this work,Co microspheres,microflakes and dendritic crystals were fabricated by a simple solvothermal method.The Co microflakes exhibits strong,broad,and thin wave-absorbing properties from the C～Ku(4~18 GHz)bands.SEM characterization results show that the diameter of Co microflakes is 12~78 μm and the thickness of Co microflakes is 0.1~0.5 μm.VSM measurement shows that the Co microflakes have excellent static magnetic properties,with a saturation magnetization of 148.6 A·m²/kg and a coercivity of 0.96 A/m.Electromagnetic performance tests show that Co microflakes have strong dielectric loss and magnetic loss capabilities.When it is used as filler,the strongest reflection loss(RL_max)is as high as 62.77 dB at 5.0 GHz,the effective absorption bandwidth is 1.2 GHz,and the thickness is only 2.37 mm.Co microflakes have a wide absorption frequency(completely cover C,X and Ku bands),strong reflection loss and thin thickness,providing a good model material for rationally designing thin,light,wide and strong electromagnetic wave absorbers.