New cobalt-deposited iron oxide particles prepared by photochemical reaction

Particles having high values in both coercivity and saturation magnetization are prepared by depositing metallic cobalt on γ-Fe2O3particles using photochemical reaction. EPMA and XPS depth profiling show that cobalt layer is formed on the γ-Fe2O3particles. When the cobalt layer of the particles is dissolved in hydrochloric acid, the coercivity and saturation magnetization of the particles are decreased to the values of pure γ-Fe2O3particles. The higher coercivity and saturation magnetization of the particles are attributed to the cobalt layer on the γ-Fe2O3particles.