Magnetic properties of iron nanoparticles in mesoporous silica matrix

Abstract Anisotropic iron nanoparticles were successfully synthesized within the pores of mesoporous silica matrix by intercalation of hydrophobic iron complex (Fe(CO)5) into the hydrophobic part of the mesoporous silica-surfactant composite. It was shown that the particles are uniform and well ordered in the matrix and their shape and size are in good agreement with that of the pores. The samples demonstrate spin-glass-like behavior at low temperatures, which transforms to the superparamagnetic one with temperature increases. Nanoscale-related magnetic properties were investigated by polarized SANS. It was shown that hysteretic and the spin-glass-like behavior may be attributed to bunches of the iron nanowires with average radius of 4.7 nm.