Effects of SiO2 content on the structure and magnetic properties of L10-FePt nanoparticles synthesized by the sol-gel method

► SiO2-coated L10-FePt nanoparticles with various SiO2 contents were successfully synthesized by the sol-gel method. ► Due to the silica coating, agglomeration is restrained even if the annealing temperature increases up to 700 °C. ► The silica shells decrease magnetic dipole coupling between FePt nanoparticles. ► The SiO2-coated L10-FePt nanoparticles show a high coercivity of 8096 Oe at room temperature.