The microwave dielectric, magnetic, and absorption properties of natural sands

Recently, much effort has been made into the study of the microwave absorption performance of various materials. In this study, we present such performance investigations of natural sands through microwave dielectric and magnetic measurements using the transmission line technique. The results show that at small thickness, barely any absorption is observed; large and wide-range absorption is displayed across the entire 1.0 ​GHz to 18.0 ​GHz frequency when the thickness is increased to a substantial value (which needs to be reduced to be more practically useful with new materials). The contributions of the permittivity and permeability on the microwave absorption are revealed upon the comparative studies of the microwave absorption performance under the assumption of zero electrical or magnetic relaxations. Magnetic relaxation instead of electrical relaxation seems to play a large role in the microwave absorption, which can be eventually related to the trace amount of impurities in the natural sand.