Effects of Mg or Sr Doping on the Intrinsic Characteristics and Absorption Properties of Micro-nano BaFe12O19 Hollow Multiphase Ceramic Microspheres

Micro-nano BaM hollow multiphase ceramic microspheres (HMCMs) and Mg-doped and Sr-doped BaM HMCMs were prepared by combining the low-temperature self-reactive quenching method with heat treatment. The effects of Mg or Sr doping on the intrinsic characteristics and absorption properties of micro-nano BaM HMCMs were investigated. The results showed that Mg or Sr doping modified the phase compositions and particle size distributions of the HMCMs. The Mg- and Sr-doped BaM HMCMs had large real and imaginary permittivities and large real permeabilities at low frequencies relative to the, undoped HMCM. To maximize the absorption properties of the undoped and Sr- and Mg-doped HMCMs, optimal thicknesses of 8, 10 and 10 mm were used with corresponding reflectivities of −8.2, −31.5 and −26.6 dB, respectively.