Electromagnetic absorption properties of composite mortar with graphene and manganese-zinc ferrite

Electromagnetic wave absorption of building structures plays a crucial role in safeguarding information and mitigating electromagnetic radiation. This study delves into the absorption capabilities of composite mortar made with graphene (GR) and manganese-zinc ferrite (MFO) across frequencies of 1-18 GHz. The mechanical strength, microstructural examinations, and numerical simulations to elucidate the underlying mechanisms of wave absorption in the composite mortar are investigated. The results indicate that incorporating 30 % MFO reduces the strength of mortar due to its low bonding capacity and diluting effects, whereas GR enhances the strength of mortar by facilitating cement hydration. Electromagnetic examinations reveal that MFO boosts the magnetic loss performance, while GR augments dielectric loss properties. In addition, the presence of needle, rod, mesh, and flake hydration products in the pores of composite mortar also contributes to increased wave depletion. According to the simulation of electromagnetic absorption based on the finite difference time domain (FDTD) method, the composite mortar with GR and MFO exhibits a superior performance of electromagnetic wave absorption. With the 25 mm thickness of composite mortar with 30 % MFO, an absorption below -10 dB, covering a bandwidth of 1.68-4.34 GHz are obtained, with a peak reflection loss of -22.13 dB at 3.23 GHz. Thus, by combination magnetic loss of MFO, dielectric loss of GR, and the reflective capabilities of porous mortar, a composite mortar with a better electromagnetic wave absorption can be achieved.