M-Type Ba-Hexaferrite Nanoplates with Exceptional Microwave Absorption Properties

Barium hexaferrite BaFe 12 O 19 (BaM) nanoplates have been synthesized by using a combined sol–gel technique and molten salt method through high-temperature calcination. The components, morphology, and magnetic and microwave absorption properties of BaM were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), and vector network analysis (VNA). The experimental results indicate that the obtained nanoplates exhibit the smallest average grain size and the highest saturation magnetization strength at the calcination temperature with 950 °C. Meanwhile, the electromagnetic adsorption parameters show that the obtained nanoplates reach the maximum reflection loss value of −56.79 dB at 1.74 mm and the maximum effective absorption bandwidth of 4.01 GHz at 2.5 mm. The dielectric and magnetic loss tangent curves demonstrate that the mechanism of dielectric loss is mainly dominated by the nano intrinsic effect of these nanoplates. The remarkable microwave absorption property of the BaM nanoplates demonstrates their significant potential for application in advanced microwave absorption devices.