Gas phase preparation of spherical core-shell α''-Fe_(16)N2/SiO2 magnetic nanoparticles

摘要

Well-dispersed spherical core-shell α"-Fe_(16)N2/SiO2 ferro-magnetic nanoparticles were successfully synthesized from core-shell α-Fe/ SiO2 nanoparticles. Introduction of oxidation prior to the nitridation process gives 90% of α"-Fe_(16)N2 phase contained in the core while no phase change is observed without oxidation. Saturation magnetization and coercivity are 148 emu g~(-1) and 1.82 kOe, respectively.