Controlling electromagnetic and mechanical behaviors of geopolymer matrix with nano-SiO2@Fe3O4 magnetofluid for soft magnetic applications

Abstract

Nano-SiO2@Fe3O4 magnetofluid modified geopolymer (NMMG) is presenting promising application potential in the field of magnetic building materials by virtue of its high magnetic permeability. This work aims to reveal the modification mechanisms of nano-SiO2@Fe3O4 magnetofluid on the electromagnetic and mechanical behaviors of geopolymer matrix, thus providing theoretical guidance for the engineering applications of NMMG. The results show that the introduction of nano-SiO2@Fe3O4 magnetofluid enhances the magnetic exchange energy between adjacent magnetic moments inside the geopolymer, thus weakening the coercivity by intensifying the rotation of magnetic domains inside the geopolymer, which provides a new idea for the application of NMMG in the field of soft magnetic construction materials. In addition, when the concentration of nano-SiO2@Fe3O4 magnetofluid reaches 9.4 vol%, good balance is found in the electromagnetic and mechanical behaviors of NMMG material. In that regard, NMMG can achieve satisfactory mechanical performance, ensuring as well low eddy current and hysteresis losses under alternating magnetic field, which reflects its great potential in soft magnetic applications.