A novel preparation and surface decorated approach for alpha-Fe nanoparticles by chemical vapor-liquid reaction at low temperature

摘要

In the paper, alpha-Fe nanoparticles with an average size of 17 nm were prepared by a low temperature chemical vapor-liquid reaction, using Fe(CO)_5 liquid and NH_3 gas as the starting materials. Transmission electron microscopy (TEM) images show that the as-prepared n-Fe nanoparticles are hexagonal and coated by a 6-nm-thickness chemical surfactant. The X-ray diffraction (XRD) patterns of the nanoparticles before and after aging in air prove that their resistance against oxidation has greatly improved, which is attributed to decorated layers of their surface. The hysteresis loops recorded by vibrating sample magnetometer (VSM) reveals that the coercive field H_c is 1.771 X 10~4 A m~(-1) and the saturation magnetization M_s is 0.915 T.